US investigators operating under a veil of secrecy spent two hours in the isolated Kamunting detention centre in Perak today, questioning a terror suspect over links to the Sept 11 terror attacks.

Three men believed to be Federal Bureau of Investigation (FBI) agents were driven in a car with United States diplomatic plates into and out of the Kamunting camp, some 300 kilometres north of Kuala Lumpur, without speaking to waiting reporters.

The agents were there to interrogate Yazid Sufaat, who is alleged to have had connections with Zacarias Moussaoui, the only person to have been put on trial in the United States over the attacks on New York and Washington last year.

Yazid's lawyer, Saiful Izham Ramli, told AFP last week that the former army captain would cooperate with the US investigators, whose presence in Malaysia has not even been acknowledged by the US embassy here.

The US news blackout is believed to be aimed at minimizing any risk of offending the government, which reacted angrily to suggestions in some western media early this year that Malaysia was a "launchpad" for the Sept 11 suicide hijackings.