George Pell should return to Australia to face the royal commission into child sex abuse over allegations he tried to bribe a victim of sex abuse, Opposition Leader Bill Shorten has said.

Fronting the press at a Melbourne school, Mr Shorten said Ballarat’s abuse victims should “be treated with respect, not just legal strategy”.

“I do believe that George Pell should help the royal commission and if that means coming back to Australia to cooperate with the royal commission he should,” Mr Shorten said.

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“The pain has gone on too long and we all have to stand up.”

Cardinal George Pell has denied allegations that surfaced during the Royal Commission into Institutional Responses to Child Sexual Abuse.

Cardinal Pell was has been accused of trying to buy David Ridsdale’s silence in 1993 over abuse allegations by his uncle, Father Gerald Francis Ridsdale, Australia’s worst paedophile priest.

The commission also heard from Timothy Green, 53, who said when he was 12 or 13 he told Father Pell – who was assistant priest at the Ballarat East parish from 1973 to 1984 – Brother Edward Vernon Dowlan was abusing children at St Patrick’s College in late 1974.

“Father Pell said `don’t be ridiculous’ and walked out,” AAP reported Mr Green told the commission.

“His reaction gave me the impression that he knew about Brother Dowlan but couldn’t or wouldn’t do anything about it.”

Cardinal Pell said he has no recollection of the conversation and can’t remember Mr Green.

“To the best of my belief, this conversation did not happen.”

About 140 men have come forward with reports of abuse at Catholic institutions in Ballarat.

Cardinal Pell issued a statement from Rome where he is looking after the Vatican’s finances.

He said he was “horrified” by the allegations aired during the hearings and victims’ suicide.

But on the allegation he was told of the abuse, Cardinal Pell said he still did not recall it.

“To the best of my belief, this conversation did not happen. I stand by my previous statements,” he wrote.

And he said he was “committed to complete cooperation with the royal commission”.

“I will address in full all matters it wishes to raise in any statement requested from me before I make any further comment.”

Prime Minister Tony Abbott said on Thursday that Cardinal Pell’s cooperation is a matter for him.

“Look, these are properly matters for the royal commission, properly matters for the royal commission and for him,” he said.