Former Victorian detective Paul Dale lied about his relationship with gangland boss Carl Williams because he realised he was a suspect in a double homicide, a court has heard.

Dale is being tried before a Supreme Court jury over allegations he lied to the Australian Crime Commission at two hearings in 2007 and 2008 about the nature of his relationship with Williams.

In his opening address on Thursday, crown prosecutor Christopher Beale SC said Dale lied at both hearings, which were related to the 2004 murders of career criminal Terry Hodson and his wife Christine.

He said Dale lied that he had met Williams on only three occasions, for work purposes.

"He told the lies because he realised he was suspected of involvement in the murders," Mr Beale said.

"We say the truth is that he had an ongoing secret relationship, an off-the-record relationship, with Carl Williams ... right up until the time of the murders of the Hodsons."

Mr Beale said that before his death, Hodson had agreed to give evidence against Dale, who had been suspended without pay from Victoria Police after being charged with burglary and drug offences in 2003.

Hodson was due to give evidence at Dale's committal hearing, and the charges against Dale were dropped soon after the murders.

Dale has pleaded not guilty to 12 charges of giving false evidence to the ACC.

Mr Beale said Dale had spoken to Williams in February 2004 using the phone of his friend, criminal barrister Nicola Gobbo.

In a tape of the conversation, played to the jury, Dale is heard telling Williams he had been trying to get onto him for quite some time and was "hoping to catch up".

"I have been wanting to f***ing see you for ages," he tells Williams.

A few months later on May 2, days before the murder of the Hodsons, Dale made two brief calls to Williams' father George, asking him to tell Carl to call Ms Gobbo.

Two days later, Carl told Ms Gobbo during a phone conversation that a drunken Dale had called his father.

Mr Beale said that call between Williams and Ms Gobbo indicated there was more to Dale's relationship with Williams than what he told the ACC.

"Why does Carl believe it is Dale if the relationship is as limited as Dale said?" asked Mr Beale.

The hearing continues.