A senior church official has asked to amend his evidence to a commission on child sex abuse after the church’s law firm contacted him.

A senior church official has revised his evidence to the Royal Commission on Child Sex Abuse following a flurry of late night emails with a law firm representing the Catholic Church.

Michael Salmon, director of the Catholic Church’s NSW/ACT Professional Standards Office, said on Friday he wanted to submit a supplementary statement to assist the commission.

He was contacted on Thursday evening by law firm Gilbert + Tobin and asked to clarify statements he made about a mediation session with an abuse victim who had concerns the Marist Brothers knew of and did nothing about abuse at a Cairns college.

A string of emails between the law firm and Mr Salmon, which culminated in him agreeing to a revised statement at about 9pm (AEDT) on Thursday night, were examined by the commission on Friday.

During a public hearing into Towards Healing, the internal church process for dealing with abuse complaints, it became an issue whether a Marist brother lied at a mediation session for a man referred to as DK about what he knew about a brother who has since been jailed.

Mr Salmon facilitated the 2010 session with DK, who was sexually molested when he was a student at the St Augustine’s Marist College in Cairns in 1976.

Evidence from Mr Salmon on Wednesday and Thursday suggested that the conversation DK had with former college principal Brother Gerald Burns and another clergy member covered what they knew of inappropriate behaviour by Ross Murrin in relation to DK and other boys.

Murrin was jailed in 2008 for offences against children at Sydney schools. He had been moved to Rome by the order in 2002 but voluntarily came back in 2007 to face charges.

In his evidence on Thursday, Br Burns told the commission DK never asked him about offences against other boys but only about his own situation.

Br Burns also said a file note from Mr Salmon written after the mediation session which suggested otherwise was inaccurate.

Commission chairman Justice Peter McClellan asked Mr Salmon if lawyers told him during the Thursday night exchanges whether there was an issue as to whether Br Burns had told DK the truth.

Mr Salmon said he had not been told that.

He said that he wracked his brains for further recollections of whether the discussion had been about just DK, or other students and could only remember the discussion was all about DK.

Justice McClellan reminded Mr Salmon that he had asked him twice during his original evidence about the context of the conversation between DK and the brothers.

“I put it to you it was beyond DK and you said `Yes, Yes’,” he said.

He said DK was also concerned that the brothers had not helped Murrin, who he saw as a sensitive person, and this was the context of his “beyond DK” responses.

Mr Salmon said he was aware DK had broader concerns about whether the brothers had knowledge of the abuse at the school but left it to him to raise it at the mediation meeting because DK had come to the session with detailed notes and was “not a shrinking violet”.

DK had left the mediation happy and on good terms with the brothers, he said.

Mr Salmon told senior counsel assisting the commission Gail Furness he had taken the advice of the lawyers when they rejected his suggestions for amendments as not relevant to the statement because it did not alter what he was trying to say.