Sens. Carl Levin, D-Mich., and John McCain, R-Ariz., said in a joint statement Wednesday that Dr. Shakil Afridi had acted heroically and in Pakistan's interests by providing U.S. intelligence with leads on bin Laden.
"We call upon the Pakistani government to pardon and release Dr. Afridi immediately," the senators said. "At a time when the United States and Pakistan need more than ever to work constructively together, Dr. Afridi's continuing imprisonment and treatment as a criminal will only do further harm to U.S.-Pakistani relations, including diminishing Congress' willingness to provide financial assistance to Pakistan."
Afridi drew a 33-year prison sentence after a tribal court convicted him of treason for conducting a fake vaccination campaign in Abbottabad that provided the United States with evidence bin Laden was living there, The New York Times reported.
Other senior U.S. lawmakers and officials they were disappointed by the sentence and accused Pakistan of overreacting to Afridi's efforts to find bin Laden.
A senior U.S. official with knowledge of counter-terrorism operations in Pakistan told The Washington Post Afridi was not asked to spy on the Pakistani government.
"He was asked only to help locate al-Qaida terrorists, who threaten Pakistan and the U.S.," the unnamed official said. "He helped save Pakistani and American lives. His activities were not treasonous, they were heroic and patriotic."
Levin is chairman and McCain is the top Republican on the Senate Armed Services Committee.