"He'll go back to his old hunting grounds": Samantha Knight's killer could be days away from release.

With AAP.

On the night of August 19, 1986, Tess Knight came home from work to her empty Bondi unit, where she was expecting to find her nine-year-old daughter, Samantha. It was a Tuesday, and Samantha should have been home from school.

But when Tess discovered that the neighbours hadn’t seen her daughter all afternoon, she quickly released something was wrong. Tess called the police.

What ensued was one of the biggest police searches in New South Wales’ history.

But it was sixteen years until what happened to Samantha Knight became known, when a man named Michael Guider was arrested for her murder in February 2001.

Guider pleaded guilty to the 1986 manslaughter of the Bondi schoolgirl, which saw him handed a 17-year prison term in 2002.

The court, at the time, heard Guider had given the nine-year-old an overdose of a sleeping drug.

The gardener and part-time babysitter was already serving a 16-year sentence after pleading guilty in 1996 to dozens of child sex offences against 11 victims.

Some of Guider’s other victims, too, had been drugged so he could photograph and abuse them.

To date, Guider has never revealed the location of Samantha Knight’s body. And now his sentence will expire on June 6 and he is expected to walk from prison aged 69.

A victim’s warning: Sydney will become Guider’s “hunting ground”.

Chantelle Hamilton, one of Guider’s surviving victims, is warning that Sydney will become a “hunting ground” if he is released in less than two weeks. Hamilton is marching down Bondi Beach promenade on Saturday alongside Sam’s school mates and locals to protest his release.

“Keeping pedophiles in jail is important, they’re an infestation in the community,” Ms Hamilton said.

The now-30-year-old mother has already marched in Adelaide, where she lives, but wants to protest in the community still haunted by Guider’s crimes.

"Bondi remembers, people remember seeing Samantha's missing poster hung up around the place, they'll remember searching for her," Ms Hamilton said.

"But her body was never found, there's been no real closure for her mum, her family or the community."

Ms Hamilton said Guider's refusal to reveal the location of Samantha's body "rubbed salt in the wound".

"He has no remorse, he's not sorry, he just wants to do his time and get out - if he felt differently he would have given Samantha's family peace," she said.

The judge who sentenced Guider in 2002 said his continued use of drugs on children following Samantha's death showed he remained a danger.

Ms Hamilton echoed those words 17 years later.

"He's smart, he's careful, he'll go back to his old hunting grounds," she said.

"His age won't diminish him as a predator or a threat, I think people should be scared and outraged."

"There should not be any second chance."

The NSW Attorney General is preparing to launch a last-minute legal bid to keep Michael Anthony Guider behind bars while public support builds for new laws to keep him locked up indefinitely.

Attorney General Mark Speakman's office is expected to begin an application for a 12-month continuing detention order in the NSW Supreme Court on Monday.

The government wants that followed by a five-year extended supervision order which will see Guider monitored after his release.

But Ms Hamilton wants legislators to stop child killers being released if they won't offer up the location of their victims' bodies.

Her online petition for stronger laws has garnered almost 130,000 signatures in three months.

"People have had enough, if you hurt a child, rape a child, kill a child there should not be any second chance," she said.

You can sign the petition to protest against Michael Guider's release by Chantelle Hamilton here.