PESHAWAR, Pakistan — A Pakistani doctor who helped the Central Intelligence Agency locate Osama Bin Laden through a fake vaccination campaign in the city of Abbottabad was convicted on Wednesday of treason and sentenced to 33 years in prison, a senior official in Pakistan said.

He had been charged under a British-era regulation for frontier crimes that unlike the Pakistan criminal code does not carry the death penalty for treason. Under Pakistani penal law, he almost certainly would have received the death penalty, a Pakistani lawyer said.

The decision appeared likely to add to the strained relations between Pakistan and the United States at a time when the two countries remain at loggerheads over reopening supply lines through Pakistan to Afganistan.

In January, Defense Secretary Leon E. Panetta confirmed that the United States had been working with Dr. Afridi to gain access to Bin Laden's compound in Abbottabad in the months before the raid. American officials had previously said that the doctor been running a phony hepatitis B vaccination program as a ruse to obtain DNA evidence from members of Bin Laden’s family, who were thought to be hiding in the city.

According to Pakistani security officials, Dr. Afridi admitted to helping the C.I.A. before the raid by Navy Seals that killed Bin Laden in May 2011. That operation angered Pakistani officials who viewed it as a violation of the country's sovereignty and because they were not told about it ahead of time.

Dr. Afridi was detained by Pakistan’s Inter-Services Intelligence from near Peshawar in the weeks following Bin Laden's killing. A judicial commission in Pakistan investigating the circumstances leading to the death of Bin Laden had recommended in October that Dr. Afridi be charged with high treason.

American officials have said that while Dr. Afridi never gained DNA samples from inside the compound, his work aided the mission that led to Bin Laden's death. Secretary of State Hillary Rodham Clinton has called for Dr. Afridi to be released.

Mr. Panetta expressed anger in a television interview in January that Dr. Afridi had been charged with treason. “For them to take this kind of action against somebody who was helping to go after terrorism, I just think is a real mistake on their part,” he said.