ISLAMABAD – A Pakistani doctor who led a phony vaccination campaign aimed at helping the CIA pinpoint Osama bin Laden’s whereabouts was convicted of treason Wednesday and sentenced to 33 years in prison, a decision that is likely to further erode Washington’s fragile relations with Islamabad.

U.S. officials have been seeking the release of Shakeel Afridi ever since his arrest by Pakistani authorities following the secret American commando raid that killed the al-Qaida leader in his compound in the military city of Abbottabad a year ago.

In January, Defense Secretary Leon E. Panetta told CBS’ “60 Minutes” that Afridi had provided intelligence that assisted the raid and criticized Pakistan’s arrest of someone involved in helping track down the world’s most wanted man.

From the start, however, Pakistani authorities have regarded Afridi as a traitor and have ignored Washington’s calls for his release. He was tried in a tribal court in Khyber, the region along the Afghan border where he once was designated the chief surgeon. The trial was held behind closed doors, and no members of the media were allowed.

Under Pakistani law, Afridi could have been given the death penalty. In addition to the 33-year term, he was also fined about $3,500.

The phony hepatitis B vaccination scheme was aimed at obtaining DNA evidence from bin Laden’s residence.