The man whose arrest in Pakistan three years ago led to a terror alert at financial centers in New York, New Jersey, and Washington D.C., has been released in Pakistan.

While the arrest and computer seizure of Mohammed Naeem Noor Khan made big headlines in August 2004, it turns out he may have been cooperating with Pakistani authorities before his arrest.

"Khan apparently had agreed to cooperate with Pakistani officials and was engaged in a sting operation against al Qaeda when his name showed up in the U.S. press as part of a story about planned attacks in the U.S., which appeared during the U.S. presidential election," according to Richard Clarke, an ABC News consultant and former U.S. counterterrorism official. "Khan may have bargained for an early release because he cooperated."

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A lawyer for Khan told the Blotter on ABCNews.com his client was never charged with any crime since his detention in July 2004.

U.S. officials said following Khan's arrest, they believed he had played a key operational role in gathering information about American targets.

When authorities recovered Khan's laptop computer, they said they found detailed pictures and surveillance reports on several financial targets in the U.S. along with what was then identified as plans for a coordinated series of attacks on the London subway systems.

The computer files were written in English and contained narration of the travels of al Qaeda members throughout the financial buildings in the U.S., offering step-by-step commentary with rich details, according to law enforcement sources.

Following his arrest, Khan reportedly provided information that led to a series of arrests in the United Kingdom.

The State Department did not immediately reply to requests for comment on his release today.

This post has been updated.

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