Peter Dutton berates 'idiot' Zaky Mallah

Home Affairs Minister Peter Dutton says Singapore "won't cop idiots" like Australian Zaky Mallah as the former terror suspect awaits deportation back to Australia.

Mallah, who was jailed in 2005 for threatening ASIO staff but cleared of terrorism charges, was interrogated for five hours after landing in the island republic on Tuesday night.

He was deemed a security threat ahead of next week's summit between US President Donald Trump and North Korean leader Kim Jong-un.

Mr Dutton said he hated talking about "attention seekers" like Mallah.

"He's this 'zealot' and he's 'so principled' yet he runs around in Nike gear, he's got trendy western gear on, so he's a joke this guy," the minister told Sydney radio 2GB on Thursday.

"He's an attention-seeker and I hate even talking about him, but he'll be on a plane I suspect, back to Australia very soon. Singapore won't cop idiots like that."

Mallah alerted the Seven Network to his predicament before his phone was confiscated.

"They asked me a lot of questions about my history, my dealings with the Australian government, ASIO, my trip to Turkey, Syria," he said.

"They asked me if I was in Syria ... fighting, more or less."

Mallah was the first Australian to be charged with terrorism offences introduced by the then-Howard coalition government. The charges were later dropped.

He spent two years in prison for threatening to kill ASIO officers.

Mallah was last in the public spotlight in 2015 when he appeared on ABC television's Q&A program, which was attacked in federal political circles.