SINGAPORE - A BANGLADESHI clerk with a diseased leg triggered a major security alert in Singapore where police are hunting for a suspected extremist leader, a newspaper here reported on Thursday.

Mohamad Iqbal Hussain, 28, was limping to a canteen near a shopping mall in the city-state when an alert individual called police, according to The New Paper.

The reason: Mas Selamat bin Kastari, the alleged Singapore head of regional terror group Jemaah Islamiah, also has a limp - and is still in hiding after escaping from detention more than a week ago.

They left after briefly interviewing him, the newspaper added.

It turned out that Mr Iqbal, who works as a clerk in Dhaka, is in Singapore to seek medical treatment for a disease affecting his right leg and which causes him to walk with a limp.

'I was unwaware of what was happening,' he was quoted as saying.

'I did not know there was this dangerous terrorist on the loose. I don't speak English so I did not pay attention to the posters.'

Posters bearing Kastari's face have been plastered all over Singapore, and state that the fugitive walks with a limp from his left leg.

Police have urged the public to call a telephone hotline if they see anyone walking or running with the distinctive limp.

Kastari, who was arrested in neighbouring Indonesia in 2006 and turned over to Singapore, is accused of plotting to hijack a plane in order to crash it into Singapore's Changi airport in 2001.

He managed to escape after asking to go to the toilet during a family visit, security officials said.