The militants: Engineer who studied at Reading University is 'most wanted' suspect

Only five days ago, Indonesian counter-terrorism officials said they were urgently seeking Azahari and one other senior member of Jemaah, Noordin Top. Both men have been on the run since 2002. Ansyaad Mbai, a senior counter-terrorism official, said: "Hunting Azahari is still our top priority and our hope is that nobody, including the US and Australia, will become Jemaah's targets."

Azahari has been accused of planning the suicide bombing at the Australian embassy in Jakarta which killed 11 people and injured 180 in 2004. It was later alleged that he had been stopped by Indonesian police three times for traffic offences but had not been arrested because they failed to recognise him.

He was born in Malaysia before moving to Australia to go to university in the Seventies. He later came to Britain to take a doctorate at Reading. Known as the "Demolition Man", Azahari is believed to have trained in Afghanistan and the Philippines before he became Jemaah Islamiyah's chief bomb-maker.

Following the first Bali bombings, Indonesian police failed to catch him. Malaysian officials described Azahari as "well trained in all types of bombs, especially remote-controlled explosives. He has experience in handling large amounts of explosives."

In 2003 an Indonesian police spokesman said he was their "most wanted".