Led by Child Abuse squad boss Peter Yeomans, strike force Hermoyne is inching ever closer to a spate of charges that will leave Australia aghast.

The team has been looking at the disgraceful Colt family since December 2012. Through phone taps and interviews with children they have pieced together a terrible tale.

Mothers describe their children’s voices as “sexy”. Children are born with misshapen bodies into an environment of neglect and malnourishment bordering on systemic torture.

Girls, 7, are raped by their teenage brothers.

One of the Colts is already behind bars, but is appealing against her conviction. Her, and others in the sick clan, have provided DNA evidence that police hope will lead to charges of incest.

Sexual assault and crimes of serious neglect will also likely appear on the charge sheet.

It can today be revealed that Charlie Colt, a man accused of fathering children with his sister and then raping them, is back in Australia after fleeing to England in an attempt to escape the clutches of Yeomans and his detectives.

The Saturday Telegraph can reveal he recently returned to the waiting arms of investigators after the Child Abuse squad received a tip-off from immigration officials.

Detectives interviewed him as an extraordinary brief of evidence takes shape.

Behind the scenes

As revealed by The Daily Telegraph earlier, Charlie Colt made his mad dash to Europe in June after police applied for a court order to take DNA evidence from him. He claimed he was researching his family history and vehemently denied the allegations against him and his family members.

The latest developments came as Detective Inspector Yeomans granted an unprecedented interview to The Saturday Telegraph midway through the shocking investigation.

It marks the first time Yeomans – a decorated cop with 34 years of experience in the force – has talked in detail about the Colts and the secret life of depravity they allegedly led amongst the woods in rural New South Wales.

“I’ve never seen it before. I’ve never seen something like this before in relation to bringing up children in those conditions,” he said.

“I’ve never seen it like this before.”

Officials from the Department of Family and Community Services raided the Colts’ haunting compound in July 2012 after accusations of neglect came to their attention.

The children were severely malnourished, dirty, illiterate, unable to brush their hair or teeth and used the bush as their toilet, officers alleged.

Grandparents had sex with grandchildren, it was claimed. They allegedly tortured puppies and cats and mutilated their genitals.

“I’ve never come across something, in relation to allegations of incest, that is generational in these sort of circumstances,” Yeomans said.

“When we removed two more of the family members in January in Victoria, the conditions they were living in were just outrageous.

“Squalor is probably the best word to describe it, how they were living, in 2014, Children shouldn’t be living in those conditions.”

In all, authorities removed 12 kids from the farm as the adult Colts scattered across the country in a bid to evade police.

As the children sat down to speak with their new carers, horror stories never before imagined in Australia were told.

Some girls as young as nine claimed their father Charlie, who was also allegedly their uncle, penetrated them and how their brothers repeatedly had sex with them.

Charlie’s sister Martha, accused of also being the mother of four of his children, was slapped with an AVO in September, banning her from seeing her youngest two daughters.

Horrendous

Hers and other Colt kids had malformed features and did not know what toilet paper was when they were rescued. They were routinely encouraged to participate in sexual assault by their parents, it is claimed.

“The conditions the children lived under were horrendous,” said Peter Yeomans (pictured below).

“The human living conditions were just despicable. The quality of life for the children was outrageous, just outrageous. The health, their education or lack thereof was disgraceful.

“The family are saying one thing and authorities are saying another in terms of their education or lack thereof…It was basically non-existent. (The parents) said the children were home schooled but I beg to differ.”

Earlier this month Betty Colt, a leader among the family, was jailed over a plot to kidnap two of her children back from foster carers. She will appeal the decision in the District Court next week.

Police are investigating how the 47-year-old dole recipient is getting her money. Before Betty Colt was jailed, she was driving around in a flashy new four-wheel drive.

Her incarceration was the first of the Colts and a milestone in the investigation for police.

Police tapped the Colts’ mobile phones and listened in on conversations that hinted at their evil.

“She says his voice sounds so sexy on the phone,” read a police summary of one of the calls made by Betty to her son Bobby.

“(Betty) says that she likes his voice... ohh you can say it all night.”

Disregard

The Colts talked with a brazen disregard for the law and police. They regularly swapped phones out of fears police were listening.

But despite their stubbornness and obstructive behaviour, detectives are nearing the end of a harrowing case unique in the history of Australia and maybe the world.

“In this sort of circumstance they’ve become not part of society. That’s probably how it happens. It’s unusual in the fact that it’s been generational and that there’s abuse and there’s other alleged offences occurred,” Yeomans claimed.

“We’re looking at a whole lot of alleged offences in relation to this.

“Yes, it makes headlines because it is allegations of incest, we are investigating anything and everything in relation to this matter because there’s such a multitude of children and there’s a number of adults involved, we’re looking at all sides of it.

“I see that in the New Year we will have more of an idea of what matters we’re going forward with. We as police will be in a better position to know exactly who will be prosecuted.”

Rungs of evil

Yeomans was unable to comment on the results of recent DNA tests performed on the Colts.

Asked how the Colt case compared to other investigations by the Child Abuse Squad, Detective Inspector Yeomans said: “We charged 797 offenders last year. All of our investigations are difficult. All of them are heart wrenching. We’re probably the busiest squad within the state.”

Yeomans, who began his career as a general duties officer in 1980, said when he knocks off every day he leaves his work firmly behind the doors of Police headquarters.

Martha’s children: What happened?

Albert – When 15-year-old Albert was removed from the Colt family he told carers he and his brothers Jed and Karl used to torture animals, including puppies and cats, and mutilate their genitals. His sisters said he had sex with them. He was found with fungal infections, a hearing impairment and problems with wetting his bed.

Jed – Along with his brothers Albert and Karl, he used to show porn to his young sisters. He had sex with them and told carers of sickening acts he performed on some siblings as young as seven. He was found with tongue and feet infections, learning difficulties, hearing problems and poor hygiene.

Karl – Karl was “very thin and underweight” when carers found him. He threatened to stab some staff with pencils and to cut their throats. He walked in a shuffling fashion, made loud noises when breathing at night and exhibited fungal infections. He had sex with his little sisters.

Nadia – Carers found Nadia severely malnourished, neglected and thin. Her feet were filthy and black. She didn’t know what toilet paper was and had never seen a toothbrush. Her teeth were decayed. She said her mother and father used to photograph her naked. Her siblings repeatedly had sex with her and her father raped her.

Ruth – Ruth was found severely underweight and exhibiting dysmorphic features. She didn’t know what toilet paper was or how to bathe herself. Her feet and teeth required urgent attention. Her brothers regularly had sex with her.

Donna – Died two-weeks-old.

Betty’s children:

Tammy – Two of Tammy’s children were removed from her care in Victoria in 2013 when police found them living in squalor. Colt children said she was the girlfriend of her brother Derek. Her baby Sally, who had “a thick short neck and low set ears” died from Zellweger syndrome – a rare genetic disorder associated with incest. She told investigators she was routinely raped by her brothers, that her mother Betty encouraged the behaviour and that miscarriages were common on the Colt property.

Derek – Engaged in a long term relationship with his sister Tammy and threatened to kill her if “he couldn’t have her”. The brother-and-sister couple had three children together.

Bobby – Central to a complex case that landed his mother behind bars. In a case which Betty Colt will appeal, police alleged she recruited Bobby to help with the kidnap of his younger brother Billy. Bobby has shown improvement since moving in with carers. When he was found he lacked basic hygiene, had fungal infections on his toenails. He had a walking impairment. He commonly soiled himself and was found to be operating at a kindergarten level.

Billy – Billy is living with his brother Bobby in the care of a foster family. His mother allegedly attempted to kidnap him back last year. When the Colt compound was raided, Billy had a skin condition. He had fungal infections in his toenails. He needed urgent dental work. He had ophthalmological problems, mild hearing loss and a moderate intellectual disability.

Brian – Brian was found with fungal infections and gum disease. He did not understand showering. His teeth were decayed and required multiple extractions and restorative work. His eyes were misaligned. He was working at a Year 3 level, though he should have been in Year 6. Carers observed him place his hand on his sister Carmen’s knee and move it up her thigh. He tied his carer’s 18-year-old granddaughter up with ribbon. He regularly had sex with his close relatives on the farm.

Colin – According to interviews with the Colts, Colin regularly sexually abused his young relatives.

Jane – Suffered regular sexual abuse at the hands of her male relatives.

Petra - Suffered regular sexual abuse at the hands of her male relatives.

Joe – Had sex with his niece Kimberly and abused other girls on the farm.

Ben – Died two-months-old.

Dwayne – Was found with gum disease and extensively decayed teeth, requiring multiple extractions and restorative work. He could not read or write, count, or recognise numbers. He had sex with his sisters and other young female relatives. He told carers he had sex with an eight-year-old girl in the toilets behind his primary school. He said he was told to keep secret the fact that his father was also his grandfather (Betty Colt’s dad).

Carmen – Was “masturbated” by her niece Kimberly whilst in care. Carmen was extremely underweight when authorities found her. Her dental cavities were described as “shocking”. She was unable to clean her teeth. She required podiatry treatment. She had never seen toilet paper. Carmen told interviewers her father was her uncle Charlie. She said she had sex with her family members. She said her brothers once tied her to a tree and pulled her clothes off. Once, whilst on holidays, she reportedly kept asking a boy for sex in the shower.

Raylene’s child:

Kimberly – Was observed placing her hand inside her aunty Carmen’s skirt and abusing her. She said her uncles tied her to a tree on the Colt property and had sex with her. Her mother did nothing about the regular sexual assault inflicted on her by her uncles. She threatened to cut her caseworker’s fingers off.

When she was found she was underweight, unable to clean her teeth, use toilet paper or comb her hair. She used her fingers to eat. She required urgent podiatry attention, and was observed to have fungal infections around her toenails. She had significant dental problems, including cavities requiring urgent attention and generalised marginal gingivitis.

Tammy’s children:

Fiona – Was removed from mother Tammy’s care last year after she and her sister were found living in “outrageous” conditions in Victoria. Testing showed her parents were brother and sister.

Anna – Was removed from mother Tammy’s care last year after she and her sister were found living in “outrageous” conditions in Victoria. Testing showed her parents were brother and sister.

Sally – Died two-months-old.

Rhonda’s children

Cliff – Present when authorities swooped on the Colt compound.

Tracy – Was regularly sexually abused by her uncles.

Penny – Was regularly sexually abused by her uncles.

Alice – Testing performed in 1997 when she required a kidney revealed her grandparents were brother and sister.

Cindy – The youngest of the Colts removed from the farm and the only one whose parents were not related. She was later observed masturbating on the toilet. She had sex with her cousins in a cubby house on the property. Reports found she was forced into an anti-social life of exclusion by her mother.

Timothy – Regularly sexually assaulted his female relatives.