Former high-profile NSW Police detective Gary Jubelin has formally denied that he illegally recorded conversations while leading the search for missing three-year-old William Tyrrell.

Mr Jubelin, backed by more than a dozen supporters, faced Sydney’s Downing Centre Local Court on Tuesday for the first time since he was charged in June.

His barrister, Margaret Cunneen SC, entered not guilty pleas to four charges of using a recording device to record a private conversation.

Mr Jubelin was supported outside court by victims’ relatives, including the parents of murdered Sydney man Matthew Leveson.

“Those [four recorded] conversations were with a person about the disappearance of William Tyrrell,” the former detective said.

“I had a lawful right and an operational need to record those conversations.

“I have made no attempt whatsoever to conceal the fact I recorded those conversations and police were aware of that.”

William was playing in his grandmother’s yard at Kendall on the NSW mid north coast when he vanished in September 2014.

Mr Jubelin led an investigative team that re-examined several unsolved and suspected murders, including that of William, Mr Leveson and three children found dead in Bowraville in the early 1990s.

But, Mr Jubelin said, he was removed from those inquiries as a result of the police investigation into the recorded conversations. The 57-year-old subsequently retired from the force.

“It’s not what I wanted to do,” Mr Jubelin said on Tuesday.

“But as a direct result of the manner in which management treated me after these allegations surfaced, my position in the NSW Police became untenable.

“I could no longer continue to support victims and lock up the bad guys like I’ve done throughout my career.”

He said he had “absolutely no animosity” to the force and said it’d been a privilege working with the state’s dedicated officers.

Mr Jubelin’s supporters applaud as he arrives in court. Photo: AAP

It’s alleged Mr Jubelin illegally recorded a short conversation in late 2017 from Parramatta and made three further recordings in 2018 in Kendall – the tiny town from where William disappeared.

Two of those Kendall conversations occurred in early May and the last occurred on December 28. Each offence carries a maximum of five years in jail and a fine of $11,000.

“I have done nothing wrong and I will continue to defend myself,” Jubelin said outside court.

“It’s an incredible waste of time but the courts have to go through due process and I’ve got to respect that process.”

Matthew Leveson’s father said Mr Jubelin was a detective who worked hard, pushed boundaries and thought outside the square.

“Importantly, he considers the victims of crime always,” Mark Leveson said.

The sister-in-law of Clinton Speedy-Duroux, one of three children suspected murdered in Bowraville in the early 1990s, said Mr Jubelin had always “gone that extra yard”.

“If he says he didn’t do it, he didn’t do it,” she said.

“He’s a one-in-a-million police officer.”

Mr Jubelin was excused from appearing at his next court date on September 24.

-AAP