Accused toddler killer to face NSW trial

The man accused of murdering missing toddler Cheryl Grimmer almost 50 years ago in NSW is trying to have a crucial piece of evidence ruled inadmissible ahead of his May 2019 trial.

The Crown's case would "effectively collapse" without the evidence relating to a historic confession he's alleged to have made regarding the killing, a Sydney court has heard.

The man, who can't be named as he was an underage at the time, is charged with murdering three-year-old Cheryl after she vanished from an Illawarra beach in 1970.

He pleaded not guilty in the NSW Supreme Court on Friday and the trial was scheduled to begin in Sydney on May 27.

But the court will first hear in February the accused's application to have his alleged decades-old admission ruled inadmissible.

Prosecutor Michael Barr said it seemed the Crown case would be weak without it while the accused's lawyer, Richard Wilson, argued it would effectively collapse.

Mr Wilson said his client had previously been thoroughly investigated without charges being laid.

It wasn't until 2017 that he was extradited from Victoria and charged with the toddler's murder and Mr Wilson said any new evidence was limited.