"It was quite confronting,given that we were in such a public place ... it was definitely a step too far.

"I remember turning around to Alan and saying'Oh my God,I cannot believe I'm seeing what I'm seeing. What are we going to do?'"

She said that Mr Tudge demanded the photograph be deleted.

The Attorney-General denied the ABC's depiction of the incident and said he was considering legal action against the broadcaster.

"Four Corners'depiction of interactions in the bar are categorically rejected,"he said.

"The other party subjected to these baseless claims directly rebutted the allegation toFour Corners,yet the program failed to report that."

Four Corners journalist Louise Milligan said on Twitter she gave the minister's office two weeks to respond.

Mr Porter also disputed the nature of his meeting with Mr Turnbull.

"Malcolm put to me a rumour[about leaking] ... and towards the end of that meeting he queried whether there was any accuracy to what he described as another story he had heard,the answer was no to both of these things,"he said.

At the time of that meeting,Mr Turnbull was about to elevate Mr Porter to Attorney-General and into the National Security Committee.

"I reminded him that Canberra was full of spies,not all of them worked for us,"Mr Turnbull said.

"The risk of compromise is very,very real,it's not just the stuff of spy novels,people who put themselves into positions where they can be compromised or blackmailed are really taking risks and unacceptable risks."

Asked how Mr Porter reacted to the dressing down,Mr Turnbull said:"He clearly didn't enjoy it.

"The message was very clear that if there was reports like that,that emerged in the future that would have very,very severe consequences for his role in the ministry under my leadership."

Three months later,the revelations that Barnaby Joyce was expecting a child with his now-partner and former staffer Vikki Campion prompted the then-prime minister to introduce a"bonk ban"– forbidding ministers from sleeping with their staff.

Mr Turnbull revealed the ban was introduced not solely because of Mr Joyce's behaviour but also the reported behaviour of Mr Tudge and Mr Porter.

Ms Miller,also married,said her affair was consensual but that she felt as though she had no power in the relationship.

Their affair began in June 2017 and lasted until November.

"I lived to bitterly regret it,"she said.

"I didn’t feel I had any power at all to be able to stand up for myself."

Both Ms Miller and Mr Tudge are no longer married.

"Tonight,matters that occurred in my personal life in 2017 were aired on the ABC’sFour Corners program,"Mr Tudge said in a statement.

"I regret my actions immensely and the hurt it caused my family. I also regret the hurt that Ms Miller has experienced."