The Malaysian immigration authority recently decided to disallow Indonesian lawyer, Dr Adnan Buyung Nasution from entering the country without giving any reason. He was simply ordered to leave upon arrival at the Kuala Lumpur International Airport.

Adnan was invited by Keadilan to speak on the condition of jailed ex-deputy premier Anwar Ibrahim.

He also came with a petition signed by several key Indonesian politicians, academics and representatives from non-governmental organisations urging the Malaysian government to allow Anwar to seek the treatment of his choice.

But who is Dr Adnan Buyung Nasution? Is he an "Islamic fundamentalist" or a "Marxist-Leninist"?

Or is he simply an "extremist" whose spectre haunted Suharto throughout his 32-year rule from 1966 to 1998, and now seems to be haunting Prime Minister Dr Mahathir Mohamad and his chief secular ideologue, Abdullah Ahmad, who is the editor-in-chief of the New Straits Times .

To Malaysians who follow contemporary Indonesian politics, Adnan, 68, is no stranger.