Victorian Labor will ask state and federal police to investigate reports animals were involved in pornography allegedly distributed among government staffers and MPs.

An adviser to former Premier Ted Baillieu claimed he shared the hardcore pornography with other government staffers and MPs.

The pornography was discovered in his office after his dismissal.

Don Coulson said he kept the material on personal hard drives.

Victoria's Shadow Attoney-General Martin Pakula said police must investigate whether there were images or videos of bestiality.

"I think most Victorians would be horrified by the notion that animal pornography is being circulated in the Premier's office," Mr Pakula said.

"Apart from being simply disgusting it may also very well be illegal."

Mr Pakula said while it was not yet clear whether the possession of animal pornography was illegal, the distribution of it may be.

However, Premier Denis Napthine said the Government's lawyers had advised that there was nothing illegal in the material when it was discovered 18 months ago.

He questioned the timing of Mr Coulson's claims, considering he is in the midst of a legal battle with the government over the payout he received at his dismissal.

"For 18 months this same person has maintained when interviewed by lawyers, by independent legal people, he has claimed consistently, that nobody else has had access to this material," he said.

"(These are) absurd claims from a disgruntled, disaffected person who was sacked from my office."

Dr Napthine said the Government would welcome the involvement of police.

"I think they will confirm what has already been discovered," he said.

Victoria's Deputy Police Commissioner Graham Ashton told 7.30 Victoria that he doubted there would be a need for a police investigation unless it emerged children were being exploited.

"Certainly the ethical side of it would be questionable but I'm not thinking from what I've seen to date that it would fall in the police bailiwick," he said.