Washington ? New York City investigators are attempting to retrace the steps of an al-Qaida suspect who was arrested last week in Britain and is believed to have been sent by Khalid Sheik Mohammed, alleged mastermind of the Sept. 11, 2001, attacks, to case financial targets there in early 2001, according to several law enforcement officials.

As the ripples from a recent spate of arrests and computer discoveries became apparent Friday, law enforcement officials and documents disclosed that Eisa Hindi is believed to have been dispatched to New York with two other al-Qaida members whose mission was to take photographs and document security around symbolic financial buildings.

By retracing their steps and interviewing people identified in the surveillance photos, such as security guards on the job at the time, investigators hope to discover someone who may have been in contact with Hindi and might know more about his contacts in the United States, one law enforcement official said.

Several counterterrorism officials said Saturday that Hindi was not believed to have been in the United States since early 2001. They also disputed news reports that Hindi had come to Washington to surveil buildings.

Counterterrorism officials said Hindi was an alias for Issa al-Britani, who is a subject of the recently completed report on the 2001 terrorist attacks. Under interrogation, Khalid Sheik Mohammed described al-Britani as a trusted al-Qaida operative whom he sent to conduct surveillance of possible economic and Jewish targets in New York. Mohammed told interrogators that the casing mission was ordered by Osama bin Laden.

Mohammed, who has been in CIA custody in a secret location since his capture last year in Pakistan, also told interrogators he sent al-Britani in late 1999 or early 2000 to Kuala Lumpur, Malaysia, to meet with Riduan Isamuddin, the top al-Qaida figure in Southeast Asia who is better known as Hambali. Hambali is also being held by the CIA.

The 9-11 commission report said al-Britani offered Hambali addresses of individuals in California and South Africa who al-Britani said could help Hambali.