A Pakistani doctor who helped the United States find Osama bin Laden was imprisoned for aiding militants and not for links to the CIA, as Pakistani officials had said, according to a court document released on Wednesday.

Last week, a court in the Khyber tribal region near the Afghan border sentenced Shakil Afridi to 33 years in jail. Pakistani officials told Western and domestic media the decision was based on treason charges for aiding the CIA in its hunt for the al Qaeda chief.

But in the latest twist in the case, the judgment document made available to the media on Wednesday, states Afridi was jailed because of his close ties to the banned militant group Lashkar-e-Islam, which amount to waging war against the state.

While the document stated there was evidence that Afridi "has been shown acting with other foreign intelligence agencies", it noted the court in Khyber had no jurisdiction to act on that.

But the court recommended that the evidence may be produced before an appropriate court for further proceedings.

It was not clear whether the revelation about the actual charges could help defuse tension between Washington and Islamabad over Afridi's imprisonment.

U.S. officials hail him as a hero who helped the CIA track down bin Laden, who was killed by U.S. Navy SEALs in a raid in the Pakistani town of Abbottabad in May last year.

Defense Secretary Leon Panetta suggested on Sunday that the decision to imprison Afridi would hurt efforts to repair relations between the United States and Pakistan that were damaged by bin Laden's killing.

Many Pakistanis were infuriated by the unilateral U.S. raid to get bin Laden in a town just a two-hour drive from the capital, Islamabad, and they see Afridi as a villain who conspired against the state and brought unwanted scrutiny of Pakistan's attitude to militants.

One of the doctor's lawyers, Samiullah Afridi, was baffled after reading the verdict, which he also received on Wednesday.

"These charges against him are very different from the ones we were told earlier," he told Reuters.

"The earlier allegations against him were very serious. We deal with issues like this every day in the courts, of people accused of helping militant groups. So it's not that big an issue for us to defend."

Afridi had been working with the CIA for years before the bin Laden raid, providing intelligence on militant groups in Pakistan's unruly ethnic Pashtun tribal region, said a former Pakistani security official.

Afridi's brother, Jamil, described the treason charges as baseless and said the doctor was being made a scapegoat. REUTERS