Former terrorism suspect Zaky Mallah has reportedly been detained after flying into Singapore and is due to be deported.

The Seven Network reports the Australian man – the first to be charged with terrorism under the laws that were introduced by the Howard government – was interrogated for five hours after landing in the island republic on Tuesday night.

“They asked me a lot of questions about my history, my dealings with the Australian government, Asio, my trip to Turkey, Syria,” Mallah told Seven.

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

Mallah alerted Seven to his situation before his phone was confiscated.

He told Seven he was seen as a security threat ahead of next Tuesday’s expected summit between the US president, Donald Trump, and North Korean leader, Kim Jong-un.

Mallah was found not guilty of preparing a 2003 suicide attack on a Sydney commonwealth building after being held for two years in Goulburn jail.

He pleaded guilty to another charge of threatening a commonwealth official.

He was in the public spotlight again in 2015 when he appeared on the ABC’s Q&A program.

Dfat confirmed to AAP an Australian had been detained in Singapore but would not comment further for privacy reasons.