Before the sun rose, the informant donned a white Islamic robe. A tiny camera was sewn into a button, and a microphone was buried in a device attached to his keys. The undercover FBI informant - a convicted forger named Craig Monteilh - then drove off for 5 a.m. prayers at the Islamic Center of Irvine, where he says he spied on dozens of worshipers in a quest for potential terrorists. Monteilh's mission as an informant backfired. Muslims were so alarmed by his talk of violent jihad that they obtained a restraining order against him. He had helped build a terrorism-related case against a mosque member, but that also collapsed. The Justice Department recently took the extraordinary step of dropping charges against the worshiper, who Monteilh had caught on tape agreeing to blow up buildings, law enforcement officials said. Prosecutors had portrayed the man as a dire threat. Compounding the damage, Monteilh has gone public, revealing secret FBI methods and charging that his handlers" trained him to entrap Muslims as he infiltrated their mosques, homes and businesses. He is now suing the FBI. Officials ... confirm that he was a paid FBI informant. Court records and interviews corroborate not only that Monteilh worked for the FBI - he says he made $177,000, tax-free, in 15 months - but that he provided vital information on a number of cases.