Just months earlier, the visitor was acquitted of stealing $6 million in a string of armoured van heists in which an AK-47 machinegun was used. As a newly free man in early 2013, he had gone to visit his friend in jail for a catch-up.

During two visits, he allegedly told the inmate how he lied on the stand to beat charges over the Armaguard and Chubb van robberies in 2009, which ­included stealing bulletproof vests from police and hijacking high-performance sports cars across Sydney.

What the men, whose names are suppressed, didn’t know was that someone was eavesdropping. Police had planted a listening device under the table.

Those recordings landed the man back in court last week charged with perjury over his evidence during the marathon five-month armed robbery trial in which he was one of four ­defendants found not guilty.

If convicted in the new, judge-only trial, the possibility was raised in court that he may be retried for the robberies, from which only $500,000 has ever been recovered.

For police, the perjury charges involve an element of luck. The court heard it was homicide police who planted the bug and the target had been the inmate, who was a suspect in a murder.

But when the conversation turned to the other man’s court deception, the recordings were passed to the Robbery and Serious Crime Squad.

In arguing to have the case thrown out, the defendant’s high-profile solicitor Simon Joyner has written to the Director of Public Prosecutions to ­clarify whether the prosecuting office is “seeking to relitigate my client for the armed robbery ­offences”.

The man’s barrister, Mark Austin, told the court the DPP has so far left the matter “as an open question”.

Section 101 of the Crimes (Appeal and Review) Act says the Director of Public Prosecutions can apply to the NSW Court of Criminal Appeal for a matter to be sent for a retrial if the not-guilty finding is a “tainted acquittal”.

The conversations in question allegedly took place at the prison on February 24 and March 10 in 2013.

What the prosecution must prove is that the man was telling the truth in an unguarded ­moment, rather than simply embellishing for the sake of a good story. If it fails, he will be acquitted again.

In the time since he was found not guilty of the armed robberies, the defendant has ­cemented his reputation as one of the most feared men in NSW and is serving a long prison sentence for other offences.

Prosecutors allege the Lithgow recordings show the man lied three times while giving evidence in September 2012.

Two of the lies relate to “Mr X” — a drug dealer whose identity is suppressed after he rolled over to become the star prosecution witness in the armed-­robbery trial.

The man gave evidence at his trial that Mr X had arrived at his apartment in “the toaster” building at Circular Quay asking if he could leave a BMW car key and a bag containing a balaclava and neck warmer at his apartment. He said Mr X needed to hide the items because he was on the run over the armed robbery of the Chubb base in Lane Cove, where about $2 million was stolen.

Police found the items during a raid on the apartment. The key matched a BMW M3 found in a Marrickville garage that had seven firearms, large amounts of ammunition and a stolen police vest in the boot.

But on Thursday, Crown prosecutor John Tabuteau told the court that the jail recordings revealed the man’s evidence was “made up”.

Mr Tabuteau said the man was also lying when he claimed Mr X was responsible for the robberies. The jail recordings ­allegedly captured the man saying Mr X “has never done a robbery in his life”.

The third alleged lie was when the man threatened to have Assyrians approach Mr X’s sister, Mr Tabuteau told the court. The man claimed he was attempting to get Mr X to confess that the accused was not ­involved in the robberies and his evidence was made up.

But the real reason was to pressure Mr X into retracting his statement and not turn up to court, Mr Tabuteau claimed.

The armoured van heists were among the most brazen the state has ever seen.

Between January 12 and June 22, 2009, six armoured vans belonging to Chubb and Linfox Armaguard were robbed while delivering cash to ATMs.

In the most daring robbery on April 20, a number of men raided the Chubb base in Lane Cove just after 3.30am.

Balaclava-wearing gunmen hijacked a cash-filled van and forced the guards to drive it through the front gate, where a stolen Audi RS4 station wagon was waiting.

While loading about $2 million into the Audi, one of the men stood in the back of the truck and fired at ­approaching ­security guards, before speeding off in the getaway car.

THE ARMOURED VAN ROBBERIES

January 12, 2009

$340,000 stolen from Armaguard truck delivering cash to ATM in Potts Point. Robbers take guard’s revolver before escaping in stolen Audi RS4.

February 10

$1,425,818 stolen in a raid on a Chubb van clearing an ATM in North Sydney. The same Audi is used as a getaway car and is later found burnt out.

April 20

$1,781,810 stolen when gang raids Chubb base at Lane Cove about 3.30am. Employee is forced at gunpoint to smash the truck through the front gate and there the cash is loaded into another stolen Audi.

May 25

$2935 is stolen during failed daylight raid on Armaguard truck at prestigious Cranbrook School in Bellevue Hill. Robbers abandon raid when they can’t get into truck as students watch.

May 28

$1,097,680 stolen from Chubb van near Epping RSL. Robbers make their getaway in a

stolen BMW.

June 22

$936,360 stolen in the final robbery on Chubb van in North Sydney. Red Mitsubishi Evolution getaway car is later found burnt out.