Mr Patton said a senior constable from a southern metropolitan police station came forward to one of his supervisors late Sunday afternoon or on Monday morning.

He was interviewed on Monday and immediately suspended.

Mr Patton said the conduct was unlawful and criminal. The maximum penalty for unauthorised disclosure of information is two years in prison or $40,000 in fines.

"This is one of the most appalling breaches and I cannot recall a breach of someone's privacy like this," he said.

Mr Patton, who did not name or identify Mr Laidley, said police had let him down.

"We've breached their privacy and I do apologise on behalf of Victoria Police," he said.

Mr Patton said the senior constable disseminated the photos to six other people, some via messaging service WhatsApp. He said police were still investigating if the photos were shared between other police and if so, how many.

The senior constable's phone was being forensically examined to trace who the photo had been sent to.

The force's internal investigator, Professional Standards Command, is investigating and Victoria Police has notified the independent watchdog, the Independent Broad-based Anti-Corruption Commission.

This is one of the most appalling breaches and I cannot recall a breach of someone's privacy like this.

Deputy Police Commissioner Shane Patton

The Age has been told messages were also sent around describing compromising photos seen by police in Mr Laidley's phone and allegations about his behaviour.

Lawyers say there are transphobic overtones to the taking and leaking of the images.

"If he didn't have the same appearance then the photos probably wouldn't have have been circulated," police misconduct lawyer Jeremy King said.

Liberty Victoria's Gemma Cafarella said the leak damaged the public's trust in Victoria Police.

"Victorians need to be able to trust police with a whole lot of their personal information in order to allow police to do their job and breaches like this seriously undermines the capacity of Victorians to put that trust in police," Ms Cafarella said.

The LGBTIQ Legal Service, based in St Kilda, said the photos further eroded the relationship between police and the transgender community.

"We call on Victoria Police to take immediate against those responsible," a spokesperson said.

"As a service that provides legal assistance to transgender and gender diverse people in Victoria, we are concerned these events will only further embed the distrust many people in this community already feel towards Victoria Police."

Internally, police are furious about the breach, saying the actions of a few have damaged the goodwill they have built with the broader community.

Police Minister Lisa Neville on Monday said it was a "completely unacceptable breach of privacy".

"Police have absolutely taken this seriously, this is a real breach, it's unacceptable. They have said that themselves and I think you will see this afternoon fast action as a result of that investigation.

She said she was sent the photos on Sunday night and couldn't believe they had been shared.

"I actually got sent the pictures through a third party, I didn't see them on social media. It had been picked up on social media," she said.

It was an idiotic thing to do, unacceptable thing to do.

Police Minister Lisa Neville

"I can't understand how people can't believe that's not going to get distributed to anyone, those sort of photos. It was an idiotic thing to do, unacceptable thing to do.

"And last night I just shook my head because I knew we had the funeral [for police officer Josh Prestney] today and I didn't want to distract from the grief and issues confronting Victoria Police at the moment."

Asked whether she was concerned about transphobia within the force, Ms Neville said: "I think this had much more to do about football than anything else. But let the investigation go on, this is just unacceptable behaviour, it will be stamped on very strongly today which is very appropriate."

The incident follows an outpouring of public grief after four officers were killed after they stopped a car on the Eastern Freeway last month.

Mr Laidley, arrested outside a St Kilda home about 9pm on Saturday, appeared before Melbourne Magistrates Court on Sunday and was remanded in custody to face court again next Monday.

His lawyer Dee Giannopoulos, from Doogue & George, said taking and leaking the photo was a gross breach of privacy.

"Outraged that pictures of my client, taken by some police officer, on the sly, when in custody in interview have hit the media," she wrote on Twitter.

The Age has seen the photographs and has decided not to publish them.

Mr Laidley coached the Kangaroos for seven years, playing 151 games for both North Melbourne and West Coast.

The former premiership player is now the head coach of Maribyrnong Park in the Essendon District Football League.