Former high-profile NSW Police detective Gary Jubelin has formally denied that he illegally recorded conversations.
Jubelin led an investigative team that re-examined several unsolved and suspected murders, including the disappearance of three Aboriginal children - Evelyn Greenup, Clinton Speedy-Duroux and Colleen Walker - in Bowraville in the 1990s.
He says 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.
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.
Jubelin was supported outside court by victims' relatives.
"As a direct result of the manner in which management treated me after these allegations surfaced, my position in the NSW Police became untenable," he said.
"I could no longer continue to support victims and lock up the bad guys like I've done throughout my career."
The former detective said had "absolutely no animosity" to the force and said it'd been a privilege working with the state's dedicated officers.
It's alleged Jubelin illegally recorded a short conversation in late 2017 from Parramatta and made three further recordings in 2018 in Kendall.
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."
The sister-in-law of Clinton Speedy-Duroux, who was one of three children suspected murdered in Bowraville in the early 1990s, said Jubelin had always "gone that extra yard".
"If he says he didn't do it, he didn't do it," she told reporters.
"He's a one-in-a-million police officer."
Jubelin was excused from appearing at his next court date on September 24.