Farouk Arnaz – Indonesia's most wanted terrorist, Noordin M Top, may disguise himself by wearing a women's Islamic headscarf and a burqa, a former head of Jemaah Islamiah (JI) said during a book launch on Thursday.

The statement was made by Nasir Abbas, a JI head who now assists police, during the launching of his book "Memberantas Terorisme, Memburu Noordin M Top" ("Fighting Terrorism, Chasing Noordin M Top") in East Jakarta.

"Noordin hides by constantly moving from one place to another," Nasir said. "He takes advantage of people's friendly nature, he wears a veil and a burqa and he married local women."

The latest release is Nasir's third book about JI and his books are widely referenced by counterterrorism experts because of his background.

Nasir is one of Noordin M Top's former instructors at the Hudaibiyah terrorist camp in the Southern Philippines. His sister was married to Mukhlas or Ali Gufron, one of the Bali bombing masterminds.

Now, Nasir actively assists Indonesian police in attempts to persuade his former JI 'colleagues' to change their hardline ways.

In 2008, Nasir told the BBC that he had received an official letter from the United Nations to state that he was no longer considered a terrorist.