Investigators have confirmed that the German police had compiled a detailed report last year on the activities in the country of supporters of Osama bin Laden, whom the US blames for the September 11 attacks.

Three of the suspected suicide hijackers had recently lived in Hamburg, and international arrest warrants have been issued for two other Germany-based Arab men allegedly involved in planning the terror attacks.

Frauke-Katrin Schauten, spokeswoman for the chief federal prosecutor, on Monday said her office had received the report from the police but that it "had not included sufficient evidence to mount a formal investigation".

It is believed the report had taken a year to compile and was presented in spring 2000. Its preparation was triggered in part by the arrest in Germany in 1998 of Mamduh Mahmud Salim, believed to be a senior financial aide to Mr bin Laden.

Separately, several of Germany's powerful regional states confirmed they had started to use a controversial police investigation technique to identify alleged supporters of Islamic extremist groups. This involves preparing a standard profile of potential criminals, based on aspects such as race, age and religion, and using computer databases to identify local residents that fit that profile.

Such residents may then be targeted even if no offence has been committed. North Rhine-Westphalia, Brandenburg and Barden-Wurttemberg confirmed they were joining Hamburg and Berlin in using the profiling methods.

Fritz Behrens, North Rhine-Westphalia's interior minister said: "We want to use this approach to more effectively and precisely identify 'sleepers' in Mr bin Laden's network."

Reuters reports from Frankfurt: The Bundesbank has said its president's comments on suspicious market deals before the September 11 attacks on US landmarks were based on information already made public by other authorities.

"The assessment of president [Ernst] Welteke on the issue of possible insider financial markets dealings ahead of the terror attacks in the US is based on information made public by primarily responsible authorities," the bank said.