Cardinal George Pell, the Australian-born Vatican treasurer, is being investigated in relation to multiple allegations of child abuse in his home country, Victoria state police said.

Victoria state Police Commissioner Graham Ashton said on a Melbourne radio station program on Thursday that Victoria police had been investigating allegations against Pell for more than a year.

"The investigation is ongoing," Ashton told Radio 3AW, confirming an Australian Broadcasting Television report on Wednesday that detailed allegations of abuse dating from the 1970s to the 1990s in interviews with alleged victims.

In a statement issued in Rome on Wednesday, Pell's office said he "refutes all the allegations made on the program".

ABC said it has obtained eight police statements from complainants, witnesses and family members who were helping with the investigation. The broadcaster said it received no information from police for its story.

Ashton told Radio 3AW that police had referred the allegations against Pell to the public prosecutor's office for advice on whether to prosecute.

The public prosecutor declined to comment to Reuters on Thursday.

"While the Cardinal in no way wishes to cause any harm to those making allegations of sexual misconduct and abuse against him, the simple fact is that they are wrong," the statement from Pell's office said, adding that Pell would continue to cooperate with any investigation.

The allegations "do not correspond with the George Pell I know," said Catholic Archbishop of Sydney, Australia's most populous city, Anthony Fisher, in a statement.

Pell was a priest in rural Victoria in the 1970s and 1980s before he became archbishop of Melbourne in 1996 and archbishop of Sydney in 2001. He took the Vatican role in 2014.

Earlier this year, Pell testified at an Australian government inquiry into institutional child abuse, where he said the Church made "catastrophic" choices by refusing to believe abused children, shuffling abusive priests from parish to parish and over-relying on counselling of priests to solve the problem.