Judge Felicity Hampel on Tuesday told the four they were "worthless hangers-on" in a case that "lacked any common decency".

Judge Hampel, in the Melbourne County Court, said the victim was a "vulnerable and powerless" man who had been "outnumbered and out-muscled, threatened, humiliated and his will overborne".

Lirim Salievski, 36, of Narre Warren, Hany Ibrahim, 32, of Hallam, Angela Koutsogiannakis, 43, of Cranbourne, and Elisha Williamson, 30, of Bentleigh, each pleaded guilty to a charge of attempting to pervert the course of justice.

Salievski also pleaded guilty to false imprisonment - as did Koutsogiannakis, a beauty therapist and manicurist - and to using a prohibited weapon, while she pleaded guilty to perjury.

The court heard earlier that the victim, then aged 36 – who had difficulty reading and writing from an acquired brain injury in a motorcycle accident – had an associate who owned a Cranbourne house where Koutsogiannakis lived.

Prosecutor Sarah Thomas said in her opening that Koutsogiannakis was then in a relationship with a man who the victim had nominated in two police statements as the perpetrator of an aggravated burglary and other offences at the victim's Hampton Park home in March 2013.

Ms Thomas said the accused was remanded in custody and later had bailed refused after Koutsogiannakis told Ibrahim she was trying to have him released.

Ibrahim, an associate of Koutsogiannakis and her boyfriend, and Salievski arrived at the Cranbourne house on March 18, 2013, where Salievski demanded the victim reveal what he had told police.

He threatened him and behaved in an intimidating manner, while Ibrahim participated in the questioning and intimidation.

Ms Thomas said Koutsogiannakis took notes during the questioning and Williamson "came in and out of the area and was observing what was taking place" while Salieveski demanded that the victim make a statement to police withdrawing his allegations.

"When [the victim] told Salievski that he was unable to write, Koutsogiannakis began to write a statement for [him] to sign," she said.

Salieveski took the keys to a car the victim had driven to the house and from that time he could not leave and "feared the consequences if he left".

Salievski continued to intimidate and menace him. Koutsogiannakis completed the statement he was told to sign while Williamson walked in and out of the room and watched the proceedings.

After Salievski tapped the victim on the head with a set of knuckledusters, he and Williamson drove him to the local police station where she took him inside.

With Williamson's phone on open call to let Salievski listen as he sat in the car outside, a police officer witnessed the victim's statement and returned it to him.

Ms Thomas said the prosecution relied on the "principles of joint criminal enterprise" in relationship to Salievski, Ibrahim and Koutsogiannakis, while Williamson aided and abetted the three.

In her sentencing remarks on Tuesday, Judge Hampel noted that while the case had taken two years to finalise, the four had vigorously contested the charges "to the last minute", which included the "vigorous" cross-examination of the victim at a committal hearing.

A contested trial last month for Williamson was in day three when she pleaded guilty to her charge and Judge Hampel directed verdicts of not guilty on charges of false imprisonment and kidnapping.

She told the four she did not accept they were unaware of the victim's condition, no adequate explanation had been advanced for their conduct - and that they should be "deeply ashamed" of their roles - and there was no evidence of remorse.

Salievski, although he left school in year 9, had had a good employment history, but also long-standing issues with drug abuse and a significant criminal history, while Ibrahim also had an extensive criminal history.

Judge Hampel said Koutsogiannakis came from a strict family background that lacked love and affection and that her life went on a downward spiral after her 20-year marriage broke down and she started using drugs.

Williamson, she said, came from a stable and supportive environment with a good work history, but that after subsequent offending she had been placed on the community correction orders she had "wilfully and wantonly" breached.

Judge Hampel decide that community correction orders were not appropriate for any of them because "there is no point compelling reluctant people to engage in rehabilitation" and advised each that it was up to them to take the initiative and seek counselling or treatment.

Salievski and Koutsogiannakis were each jailed for two years and three months, while their co-offenders were each jailed for 18 months.

All of the sentences were wholly suspended for three years.

Judge Hampel told them she hoped they did breach her orders and said that if they were now not ashamed of their conduct "you never will be".