Almost 30 years after child abuse claims against Robert Hughes were first aired to police, the Hey Dad! actor has been jailed for at least six years.

Sexual predator Robert Hughes has been threatened every day he’s been in jail so far and now faces at least six more years of it.

Hughes’s lawyer Greg Walsh fears for the former Hey Dad! star who was “devastated” after being sentenced to a maximum of 10 years and nine months, with a non-parole period of six years, for the sexual and indecent assault of four young girls.

Mr Walsh said prison authorities rejected his request for Hughes to be placed in protection in the month he’s been in custody and he’ll have to spend every day of his sentence “looking over his shoulder.”

“He’s now exposed to other prisoners, he’s threatened on a daily basis,” Mr Walsh said outside court on Friday.

But his former Hey Dad! onscreen daughter and victim Sarah Monahan says she hopes he uses the time to take stock of what he did.

Ms Monahan said she was not a “vengeful person” but hoped Hughes realised he is a “very, very bad man”.

“I hope that he comes to the realisation that he probably shouldn’t have done what he did,” she told Macquarie Radio after the sentence.

While Ms Monahan said she was very happy with the sentence, Mr Walsh was shocked.

“I think you would describe it as a crushing sentence,” he told reporters and indicated he would appeal both the sentence and conviction.

Family members of the victims hugged in court as the sentence was handed down.

Mr Walsh said Hughes’s long-term partner, theatrical agent Robyn Gardiner was still supporting the actor despite having returned to the United Kingdom.

“The fact that she is not here doesn’t mean an iota that she doesn’t love and support Robert.”

Judge Peter Zahra described the once popular sitcom actor as a sexual predator who systematically exploited young girls and then relied on his position to ensure his victims’ compliance and silence when he sentenced him at Sydney’s District Court.

The actor was taken into custody in April after being found guilty of 10 charges relating to sexual and indecent acts perpetrated on four young girls in the 1980s and 1990s.

Judge Zahra said these charges represented a “systematic pattern of sexual abuse of vulnerable young girls”.

The actor, “took advantage of social and familial” relationships to carry out his “brazen” and “predatory” behaviour, he said.

After befriending the parents of a teenager, the court heard how Hughes crept into her bedroom while he was at a dinner party at her home.

Intruding on the “safety and sanctuary” of her room, he sexually assaulted her as she lay in bed.

She was around 14 or 15 years old and too frightened to say anything.

In another assault, Judge Zahra said Hughes called his victim a “good girl” after forcing her to touch him while she was staying at his home in the early 80s when she around six to eight years old.

Then, while playing the father Martin Kelly in the popular TV show he exposed himself to his Ms Monahan on set.

Hughes, who remained expressionless throughout the decision, “exploited the naivete” of these girls, Judge Zahra said.

While Hughes was only convicted of charges relating to four women, throughout his trial the court heard `tendency evidence’ from co-workers and other women who say they were abused by him as children from 1984 to 2004, despite being questioned by police in 1986 about child abuse allegations.

Hughes, the judge found, had no remorse or insight into his offending as he continued to deny the assaults.

His earliest date of release will be April 2020 when he will be aged 71.