LAHORE: A judge on Tuesday blocked any move to hand over to US authorities an American government employee under investigation for double murder, and put his name on the exit control list.

The United States on Monday again called for the release of Raymond Davis, who was arrested after killing two Pakistani motorcyclists in broad daylight in Lahore, saying that he acted in legitimate self-defence.

But a lawyer petitioned the Lahore High Court under public interest laws to block any move to hand Davis over to the United States.

“I am restraining him (from being handed over to US authorities). Whether he has or does not have (diplomatic) immunity will be decided by the court,” ruled Lahore High Court Chief Justice Ejaz Ahmed Chaudhry.

“An order is issued to put his name on the ECL (exit control list). The case is adjourned for 15 days.”

Representing the Pakistani government in court in Lahore, deputy attorney general Naveed Inayat Malik, asked the judge to give “time” to the Pakistani foreign ministry to determine whether Davis has diplomatic immunity or not.

Washington says Davis is a member of the US embassy's “technical administrative staff” and therefore entitled to “full criminal immunity”.

“He cannot be lawfully arrested or detained in accordance with the Vienna Convention,” US State Department spokesman Philip Crowley told reporters in Washington.

But the lawyer who brought the private petition, Saeed Zafar, has argued that under international law, diplomatic immunity can be waived for the most serious crimes.

Khawaja Haris, the advocate general of Punjab — the chief law officer in the province where Davis shot the motorcyclists — told the court that the Vienna Convention provides immunity to diplomats “within certain limits”.

”The federal government has to give a certificate on whether the man has diplomatic immunity or not and whether his diplomatic status is confirmed or not,” Haris said.

“What we hear about him and his immunity is through the press only. Since he is involved in a grave crime, this issue has to be decided by the court.”

But Washington is adamant that Davis is being held unlawfully and supports his version of events that he was confronted by two armed men on motorcycles.

Davis “had every reason to believe that the armed men meant him bodily harm. And minutes earlier, the two men, who had criminal records, had robbed money and valuables at gunpoint from a Pakistani citizen,” said Crowley.

When asked by visiting US congressmen on Monday to free Davis, Pakistan's President Asif Ali Zardari said: “It would be prudent to wait for the legal course to be completed”.