Sexual abuse allegations against Cardinal George Pell were not leaked by Victoria Police, the chief commissioner says.

Victoria's anti-corruption watchdog is investigating how allegations Cardinal Pell sexually abused five to 10 victims while he was a priest in Victoria became public over the weekend.

"I know we're often easy targets when it comes to alleging leaks, but I've seen no evidence we've leaked anything," Chief Commissioner Graham Ashton told 3AW radio on Thursday.

Mr Ashton said he was taking accusations Victoria Police leaked the sexual abuse allegations seriously.

"It concerned me that there was this immediate rush to allege the police have leaked something," he said.

If Victoria Police are found by the Independent Broad-based Anti-corruption Commission to have done something wrong, then "we'll absolutely wear that", Mr Ashton said.

"But a bit early to snap to rushed conclusions," he said.

Taskforce Sano - which was established to investigate historic and new allegations of institutional sexual abuse - has spent a year investigating the claims against Cardinal Pell, the Herald Sun has reported.

The police commissioner says the taskforce deals with sensitive information and does not have a track record of leaking details about its investigations.

For privacy reasons, police cannot confirm if they are investigating any allegations against Cardinal Pell.

"We're not even confirming whether or not this is even an investigation," Mr Ashton said.