A Herald Sun report claimed Victorian police are looking into allegations about "multiple offences" committed when the 74-year-old was a priest in Ballarat and Archbishop of Melbourne.
But Pell has vehemently denied the allegations, saying they are "without foundation and utterly false".
The report said a taskforce is investigating claims that the cardinal sexually abused minors by "both grooming and opportunity".
Detectives have reportedly been working on the investigation, which has involved interviewing "numerous" alleged victims over the past year.
Victorian police told Daily Mail Australia they were aware of the report but "cannot comment on any cases in which an individual has been named".
He is currently in Italy and claims he is too ill to fly nack to Australia to appear before the commission, but will testify via a video-link from Rome.
A spokesman for Pell said the timing of the leaks "is clearly designed to do maximum damage to the cardinal and the Catholic Church and undermines the work of the royal commission".
He said "these undetailed allegations have not been raised with the cardinal by the police".
"The cardinal has called for a public inquiry into the leaking of these spurious claims by elements in the Victorian Police in a manner clearly designed to embarrass the cardinal, in a case study where the historical failures of the Victorian police have been the subject of substantial evidence.
"These types of unfair attacks diminish the work of those good officers of the police who are diligently working to bring justice to victims.
The spokesman added that "the cardinal understands that several media outlets have received confidential information leaked by someone within the Victorian police. For elements of the police to publicly attack a witness in the same case study that has exposed serious police inaction and wrongdoing is outrageous and should be seen for what it is."