Pakistan's ex-ambassador to Washington was summoned by the country's top court on Tuesday as judges concluded he sought US help to curb the power of the military after Osama bin Laden's death.

A judicial commission set up by the Supreme Court has spent six months investigating an unsigned document received in May 2011 by the then US top military officer, Admiral Mike Mullen, just days after bin Laden was killed in Pakistan.

Husain Haqqani, who was forced to resign as ambassador last November, denies any wrongdoing and dismissed the commission report as "political and one-sided". He has since returned to his former life as an academic at Boston University, Massachusetts.

The commission's 600-page report to the Supreme Court held Haqqani responsible for the memo, accused him of disloyalty to Pakistan and said he had violated the constitution.

"Mr. Haqqani was the originator and architect of the memorandum. Mr. Haqqani sought American help; he also wanted to create a niche for himself making himself forever indispensable to the Americans," said a copy of Tuesday's ruling released by the court.

It was unacceptable for a Pakistani ambassador "to beseech a foreign government to with impunity meddle in and run our affairs," it said, adding that his "acts of disloyalty to Pakistan" had contravened the country's constitution.

It also questioned President Asif Ali Zardari's decision to give an "extremely sensitive" job to a man who had been living in the United States with "no obvious ties to Pakistan".

The court adjourned for two weeks and ordered Haqqani, along with witness, American businessman Mansoor Ijaz, and the petitioners, including former prime minister Nawaz Sharif, to appear when the hearing resumes. No date for the hearing was announced.

Haqqani, who refused to travel to Pakistan last time he was asked to appear before the commission, said the report was based on "dubious" claims from "a foreigner".

"In any case, the commission was created as a fact-finding body and not as a trial court so it has no right to pronounce anyone guilty or innocent of any crime," he said in a statement.

The memo was allegedly an attempt to enlist US help to head off a feared military coup in exchange for overhauling Pakistan's powerful security leadership.

Zardari reportedly feared that the military might seize power in a bid to limit the damaging fallout after US Navy SEALs killed bin Laden in the garrison city of Abbottabad, not far from Islamabad, on May 2, 2011.

At the time, reports in Pakistan said politicians were keen to clip the all-powerful military's wings and strengthen weak civilian institutions.

The bin Laden raid also exacerbated US suspicions that Pakistan's military is colluding with the Taliban and other insurgents in neighbouring Afghanistan.

The memo was controversial at a time when relations between Islamabad and Washington drastically deteriorated, as it fanned tensions between Pakistan's civilians and the military, which has ruled the country for half its existence.