ISLAMABAD (Reuters) -Pakistan has quietly released an al Qaeda suspect said to have provided information that helped reveal plans for attacks on British and U.S. targets three years ago, lawyers for the suspect and the government said on Tuesday.

Mohammad Naeem Noor Khan was arrested in July 2004, and was described by intelligence officials as an al Qaeda computer expert whose information led to the arrest of terrorism suspects in Britain and Pakistan.

Deputy Attorney General Naheeda Mehboob Ilahi said Khan had been released, but said she had no further information.

Khan’s lawyer, Babar Awan also, said his client was back with the family in the city of Karachi.

“I checked with the family and they said, ‘yes’,” Awan said. He said he did not know when Khan was released.

Khan, who was in his mid 20s at the time of his arrest in the city of Lahore, was a computer expert suspected of acting as an al Qaeda e-mail postman, passing coded messages between members.

Pakistan kept his arrest secret and an intelligence official said Khan had been cooperating with agents, continuing to pass and receive messages from his contacts after his arrest.

But the sting operation had to be quickly wound up after Khan’s name appeared in media reports weeks after his arrest.

British police captured 12 al Qaeda suspects in London apparently on information gleaned from the computer wizard.

A senior Pakistani government official had said at that time maps of London’s Heathrow airport were found on Khan’s computers, which also provided data that led to terror alerts in U.S. cities.

Khan was never charged during his three years of detention, his lawyer said.

The release comes as Pakistan is under mounting pressure from the United States to do more to tackle al Qaeda militants and their Taliban supporters in tribal lands along the Afghan border.

Al Qaeda chief Osama bin Laden is believed to be hiding somewhere in the rugged region between Pakistan and Afghanistan.