BERLIN - German prosecutors said Monday they are seeking the handover of the Islamic militant whose disclosures under U.S. interrogation in Afghanistan helped trigger Europe's terror alert.

A request for the transfer of the 36-year-old German of Afghan descent has been filed to the relevant U.S. authorities with a view to prosecuting him in Germany, a spokesman for the federal prosecutor's office said. He spoke on condition of anonymity in line with department policy.

Germany accuses Ahmad Wali Siddiqui, who was arrested by the U.S. military in July in Afghanistan, of membership in a foreign terrorist organization -- the Islamic Movement of Uzbekistan. Germany issued an arrest warrant for him in April, the spokesman said.

The 36-year-old Siddiqui is believed to have been part of the Hamburg militant scene that also included key Sept. 11, 2001, plotters. German officials have said he left Germany in March 2009 to seek paramilitary training in Pakistan's lawless border region.

Siddiqui is an old friend of Mounir el Motassadeq, who was convicted in Germany in connection with Sept. 11, and frequented the same mosque where the Hamburg-based plotters often met, German officials said last week.

Richard Holbrooke, the U.S. special representative for Pakistan and Afghanistan, said in Berlin on Monday that German officials had access to the man in U.S. custody and that the two nations were in contact to evaluate the request for his handover.

Hamburg security officials in August shuttered the Taiba mosque, known until two years ago as al-Quds, because of fears it was becoming a magnet for homegrown extremists.

U.S. officials say Siddiqui provided details on alleged al Qaeda-linked plots against Europe that prompted Washington to issue a travel alert earlier this month. Other countries issued similar warnings.

Holbrooke said the intelligence "completely justified alerting the public in Europe and the United States to be cautious, without being paranoid."

Authorities say Siddiqui left Germany along with 10 other extremists to seek paramilitary training, joining dozens of other European militants close to the Afghan border.

"They think it will be romantic to go there and fight the jihad against the Americans and the NATO forces," Holbrooke said. But in fact they are being misled and victims of the radicals' propaganda, he said.

Germany's Federal Criminal Police Office has said there are indications that some 220 people have traveled from Germany to Pakistan and Afghanistan for paramilitary training, and "concrete evidence" that 70 of those had done so. About a third of them are thought to have returned to Germany.

Pakistani intelligence officials have said they believe between 15 and 40 Germans are in the border area -- a lawless region where many top al Qaeda Arab leaders are believed to be hiding, including Osama bin Laden and his Egyptian deputy, Ayman al-Zawahri.

The head of Germany's police union, Konrad Freiberg, warned Monday that recent reports about increased extremist movements to paramilitary training camps in Pakistan and back to Germany "do not bode well."

Authorities assume that a core group of 131 Islamic extremists in Germany is capable of contemplating "politically motivated crimes with considerable impact," German news agency DAPD quoted him as saying.