The Central Intelligence Agency (CIA) was given the first name and telephone number of one of the September 11 hijackers two and a half years before the attacks on New York and Washington, according to a Tuesday report in the New York Times.
German intelligence officials gave the CIA the first name and telephone number of Marwan al-Shehhi in 1999 and asked the Americans to track him, according to the newspaper.
Al-Shehhi was determined to have piloted United Airlines flight 175 into the south tower of the World Trade Centre, the report said.
The attacks, which destroyed the World Trade Centre, damaged the Pentagon and crashed into a Pennsylvania field claimed about 3,000 lives.
The name and phone number in the United Arab Emirates were obtained by the Germans by monitoring the telephone of Mohamed Heidar Zammar, a militant in Hamburg who was closely linked to the al Qaeda plotters who masterminded the September 11 attacks, the Times said, citing German officials.
But after the Germans passed the information on to the CIA, they did not hear from the Americans about the matter until after September 11, the story said, citing a senior German intelligence official.
The CIA decided that "Marwan" was probably an associate of Osama bin Laden, but never tracked him down, the newspaper said citing American officials.
The information has become an important element of an independent commission investigating September 11, the Times reported.