Carl Williams bashed to death in Barwon Prison caught on CCTV

CARL Williams was beaten to death in prison with part of an exercise bike, police said.

Detectives at the home of George Williams, father of Carl Williams (inset), after delivering the news that Carl had been killed inside Barwon Prison today. Picture: Jon Hargest

CARL Williams was beaten to death in prison with part of an exercise bike, police said.

Police said one man had struck him heavily on the back of the head several times with a heavy object, believed to be "the stem of an exercise bike".

Police Minister Bob Cameron said this afternoon that Williams, 39, shared a unit with two men he had been "happy" with.

Timeline of Carl Williams' life

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There are only two suspects after Williams was bashed to death with an unknown weapon about 12.50pm today.

One is a person of "special interest", Mr Cameron said.

The nearest officer at the time of the bashing was about 10 metres away, but was not in the same room.

One of the men had been in the unit for 15 months, the other for nine.

The three men were able to associate for six hours a day in their unit.

Corrections Victoria admits it is very concerned by today's turn of events.

Three investigations have begun into the brutal murder: a police murder investigation, a coronial investigation and a Corrections Victoria review.

The story in this morning's Herald Sun revealing that Victoria Police paid $8000 to allow Williams' daughter to attend a top private school will be part of the investigation.

Mr Cameron said “no stone would be left unturned to get to the bottom of this murder”.

Homicide squad detectives are at the scene to investigate.

A scheduled press conference at Barwon Prison which was due to be held at 5.45pm with Detective Inspector Bernie Edwards of the homicide squad has been cancelled.

No reason has been given.

"Police believe an altercation occurred between Williams and another inmate about 12.50pm with Williams suffering head injuries after allegedly being struck about the head," a police statement read.

"Medical staff at the prison attempted to revive Williams until ambulance officers arrived, however he died at the scene.

"Police are currently working with Corrections staff to ascertain as much information as possible.

"A man is in custody and will be spoken to by police as part of the ongoing investigation."

An Ambulance Victoria spokeswoman said paramedics travelled to Barwon after a report of a suspected assault.

She said the victim had suffered head injuries and went into cardiac arrest. He died at the scene.

Paramedics arrived at Barwon Prison about 1.18pm to find the man in a critical condition after he suffered head injuries and went into cardiac arrest.

The spokeswoman said an air ambulance dispatched to take the victim to Melbourne’s Alfred Hospital was turned back after it was realised nothing could be done.

Carl's father George declined to comment to the media at his Broadmeadows home this afternoon.

A friend of George's said his mate was shattered at the loss of his son.

''He's not too good. How do you think you would be,'' he told the media pack.

The man, who would not reveal his name, said Mr Williams had no idea how his son was killed.

''We still don't know what's going on. No-one knows,'' he said. ''All I've heard has been in the news. He had a massive heart attack, that's what I heard.''

The friend, who has known Mr Williams for 20 years, said police came to the house to offer support and provided no details on what happened to his son.

'' They just came out to tell him he had counselling if he needed it,'' he said.

"We don't know how he's died or how it happened. He won't talk to = you so just leave him alone.''

The friend suggested Mr Williams was angry at the death of his son.

''You work it out,'' he said. ''It's supposed to be maximum security.''

Williams was serving life imprisonment in Barwon's maximum security Acacia unit with a non-parole period of 35 years for ordering the murders of three underworld rivals and the failed conspiracy to murder a fourth person.

He was found guilty of murdering Jason Moran, Lewis Moran and Michael Marshall.

He had one child, a daughter, with his ex-wife Roberta Williams, a convicted drug trafficker.

Williams' father George was released from prison in June 2009 after serving a sentence for drug trafficking, while his mother Barbara was found dead in 2009 after an apparent overdose.