KARACHI, Pakistan – Pakistani authorities said Sunday they had launched a manhunt for a suspect in an alleged plot to blow up trans-Atlantic jetliners who escaped from police custody a day earlier under murky circumstances. Senior Pakistani officials did not confirm the escape of Rashid Rauf, a British national of Pakistani origin, until nearly 24 hours after he fled Saturday. He was reportedly able to pick the lock on his handcuffs and overcome his captors after a court appearance in the Pakistani capital, Islamabad.

Rauf’s escape was a blow because of his value as a source of intelligence and evidence in the court case against the airline plotters, a British counterterrorism official said Sunday.

Two Western diplomats in Pakistan, speaking on condition of anonymity because of the sensitivity of the case, said the official Pakistani account of Rauf’s escape was incomplete and contained contradictions on key points. That, they said, could fuel suspicions of some form official complicity in the getaway.

The escape came as Britain was seeking Rauf’s extradition in a murder case dating back to 2002, after Pakistani courts dropped terrorism charges against him. Officials close to the case said Rauf, arrested in Pakistan in August 2006, had been expected to be sent back to the United Kingdom soon.

The British High Commission said it had requested a full accounting of events surrounding Rauf’s escape from Pakistani authorities. Britain’s relations with the government of President Pervez Musharraf have been strained over Pakistan’s suspension last month by the Commonwealth, a grouping made up mainly of former British colonies, over Musharraf’s declaration of emergency rule.

The emergency decree, imposed Nov. 3, was lifted Saturday.

Pakistan’s caretaker interior minister, Hamid Nawaz, briefed British officials on the case, the Interior Ministry said. Kemal Shah, the ministry’s No. 2 official, said Sunday that it was still unclear whether Rauf managed to flee from the court complex after his hearing or after he and guards had set off for the jail in Rawalpindi, adjacent to Islamabad.

Special security teams in several areas of the country had been assigned with the task of tracking down Rauf, Shah said.

“We are doing our best to re-arrest him,” ministry spokesman Javed Iqbal Cheema said.

Lower-ranking Pakistani officials first reported the escape Saturday and said two police officers who had been guarding the prisoner were under suspension and being questioned by authorities.

Rauf initially was described by investigators as a mastermind of the plot to blow up airliners en route from Britain to the United States using liquid explosives, but investigators later backed off on the magnitude of his role.

The uncovering of the airline plot triggered a worldwide security alert and largely was responsible for the subsequent imposing of tight restrictions on liquid items allowed in carry-on luggage.

Rauf had been fighting extradition on the 2002 murder case, which was unrelated to the airline plot. Rauf’s lawyer, Hashmat Habib, suggested to Pakistani reporters that Pakistani authorities had been reluctant to hand him over to Britain.

During the months that the plot took shape before his arrest, Rauf allegedly helped the British plotters reach Pakistani training camps, according to British and U.S. investigators. He also is suspected of serving as a liaison to masterminds in Pakistan who oversaw the most ambitious al-Qaida plot since 2001.

Once extradited, Rauf would have been tried first on the murder charges, but police intended to subject him to a thorough interrogation about the airline plot, the counterterrorism official said.

Although Rauf was interrogated for at least four days by Pakistani agents after his arrest, the statements were viewed with caution because of the possibility he may have been tortured, the official said. British investigators wanted to question him on British soil to ensure that the evidence would not be perceived as tainted in any way, the official said.

Rauf’s case was a source of friction between the United States and Britain at the time of his arrest. Although British and American investigators worked closely together, British detectives initially resisted U.S. pressure for Rauf’s capture, preferring to continue a massive surveillance operation of two dozen suspects to gather more evidence.

But U.S. counterterrorism agents pushed Pakistan to make the arrest, officials say. Word of Rauf’s capture spurred the plotters in Britain to speed up their preparations, and British police decided to round them up.

At the time of the arrests, the plotters were weeks away from attempting the attack, which would have targeted a half-dozen planes and could have matched the bloodshed of the Sept. 11 attacks, according to U.S. and British counterterrorism officials.

King reported from Karachi, and Rotella from Madrid, Spain.

AP-NY-12-16-07 1653EST