Malcolm Turnbull has slammed the ABC’s decision to allow a man acquitted of terror charges into the audience of Q&A on Monday night, labelling it a “grave error of judgment”.

During the program, government frontbencher Steve Ciobo refused to back down from controversial comments he made to a former terrorism suspect on national TV, labelling the man a “sick individual”.

Mr Turnbull’s comments, made on Sky News, followed a statement by Mr Ciobo on Monday night’s Q&A where he told Zaky Mallah that he would have no problem seeing him stripped of his Australian citizenship.

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Mr Turnbull added that the Australian Federal Police should be involved in vetting audiences for the program to ensure the safety of all participants. He had personally spoken with ABC Managing Director Mark Scott and presenter Tony Jones about the incident.

The ABC has admitted an error in judgement and says it will review the circumstances surrounding Mr Mallah’s appearance.

On Tuesday, Mr Ciobo told Sky News that Mr Mallah had posted a tweet threatening to pay money to have him kidnapped and dumped in Islamic State (ISIL) territory in Iraq.

“This just demonstrated a sick individual, frankly,” Mr Mallah told Sky News.

The majority of the #qanda audience tonight was pro Libs and pathetic. I would pay to see that Minister dumped on #ISIS territory in Iraq!

— Zaky Mallah (@ZakyMallah) June 22, 2015

Mr Mallah was found not guilty of preparing a suicide attack on a Commonwealth building after being held for two years in Goulburn jail. In a plea bargain, Mr Mallah pleaded guilty to threatening to kill ASIO officials.

His question on Monday night’s panel discussion show referenced his case in relation to a government plan allowing the immigration minister to strip citizenship from dual nationals suspected of terrorism offences.

“I had done and said some stupid things, including threatening to kidnap and kill, but in 2005 I was acquitted of those terrorism charges,” Mr Mallah said from the Q&A audience. “What would have happened if my case had been decided by the minister himself and not the courts?”

Watch the full exchange between @zakymallah and @steveciobo on @QandA. The ABC will now review Mr Mallah’s appearance http://t.co/0neRuNkRx3

— ABC News (@abcnews) June 23, 2015

Ms Ciobo replied: “From memory, I thought you were acquitted on a technicality rather than it being on the basis of a substantial finding of fact.”

“My understanding of your case was that you were acquitted because at that point in time the laws weren’t retrospective.

“But I’m happy to look you straight in the eye and say that I’d be pleased to be part of the Government that would say that you were out of the country.

“I would sleep very soundly at night with that point of view.”

The response provoked murmurs from the studio audience and an angry reaction from Mr Mallah, who said it was Mr Ciobo who should leave the country for having such views.

“The difference is, I haven’t threatened to kill anybody,” Mr Ciobo said.

Foreign Minister Julie Bishop declined to endorse the comments of her parliamentary secretary on Tuesday.

“I’m not going to go into the circumstances of a particular individual and how that would apply in the case of the new laws,” Ms Bishop told Sky News.

Labor Shadow Employment Minister Brendan O’Connor also told Sky News that Mr Mallah “seems to be a bad character” and he would “definitely not defend that person”.

Mr Mallah admitted on TV he travelled to Syria to meet with people fighting in the region, and said comments by government MPs were the reason young Islamic people were preparing to leave Australia and fight for Islamic State.

The ABC released a statement on Tuesday morning that said Mr Mallah’s comments were out of order and his appearance in the audience would be reviewed.

Director of ABC Television Richard Finlayson said the live broadcast meant it was difficult to review Mr Mallay’s comments before they aired.

“In attempting to explore important issues about the rights of citizens and the role of the Government in fighting terrorism, the Q&A program made an error in judgement in allowing Zaky Mallah to join the audience and ask a question,” Mr Finlayson said in a statement.

“The environment of a live television broadcast, however, meant it would not be possible for editorial review of the comments he might make prior to broadcast, particularly if he engaged in debate beyond his prepared question.”

The citizenship laws are expected to be introduced to Parliament later this week.

– with AAP, ABC