United Future leader Peter Dunne is all smiles in this photo, but he wasn't so happy following a fiery radio interview on Friday morning.

United Future leader Peter Dunne has clashed with a radio host in a fiery on-air interview, being labelled a "childish moron" after abruptly hanging up.

Sparks flew during Dunne's interview with Newstalk ZB Christchurch host Chris Lynch about "jihadi brides" on Friday morning.

Prime Minister John Key on Tuesday said New Zealand women were known to have taken part in "weddings" before heading to Islamic State (Isis) stronghold Syria, which pointed to the fact they were going as jihadi brides.

SUPPLIED Newstalk ZB Christchurch host Chris Lynch said of Peter Dunne: "Childish and foolish - what a moron."

Key's remarks came after SIS director Rebecca Kitteridge told Parliament's intelligence and security committee there had been a rise in the number of young New Zealand women heading to Iraq and Syria.

However, Dunne has questioned the claims, saying the allegations could be aimed at "softening up" the public before an independent review into spy agencies is released.

The Internal Affairs Minister told Lynch he had not cancelled the passports of any women, while "the mere act of marriage" did not constitute an offence under the Passports Act.

"As has been widely reported, the numbers involved are very small and frankly I think the whole issue is in danger of being completely overblown."

When Lynch pressed Dunne, asking whether he would change the law, he responded: "You're trying to make a story where none actually exists and I think that's the whole point of this."

In return, Lynch accused Dunne of being "very defensive" over the issue, saying: "I'm just trying to have a conversation - there's no need to take such a defensive...there's no need to be flippant."

NEWSTALK ZB Internal Affairs Minister Peter Dunne and Chris Lynch have a fiery conversation over the threat Jihadi Brides face to New Zealand.

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* Kiwi father of 24 killed fighting Isis

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As the two tried to talk over each other, Dunne said "it would be nice...if a person asking a question listened to the answers" and accused Lynch of having an agenda against him.

"I am defensive because I suspect your motives: I have seen various blog comments you've made about me in the past which have been far from complimentary.

"You've called me foolish, you've called me out of touch, you've called me all sorts of things, and I suspect you'll do so after this interview."

Lynch bit back, calling Dunne "childish" and saying he was taking the interview too personally.

In response, Dunne repeated his comments about jihadi brides before cutting the call short by hanging up.

Lynch had the last word, on-air at least, concluding: "Childish and foolish - what a moron."

However, the scrap has continued online, with Dunne taking to Twitter to call Lynch a "rude and ignorant person", as well as "an obnoxious piece of work".