(CNN) -- A Pakistani judicial commissioner has overturned the conviction of a doctor who is accused of helping the United States find Osama bin Laden, and has ordered a new trial, the official's office said Thursday.

Dr. Shakil Afridi will remain in prison until the new trial is held, according to the office of Sahibzada Mohammad Anees, the Peshawar judicial commissioner who overturned the conviction.

Afridi was sentenced in 2012 to 33 years in prison after a tribal court convicted him of, among other things, running a fake vaccination trial.

Pakistani authorities accused Afridi of working with the CIA to set up a fake vaccination campaign in Abbottabad to try verify bin Laden's whereabouts.

U.S. special forces killed the al Qaeda leader at an Abbottabad compound in May 2011.

Afridi had appealed the conviction. Information on why Anees granted the appeal wasn't immediately available.

Afridi's attorney, Samiullah Afridi, said Thursday he expects the retrial to begin within a month. The doctor's family has had no contact with him for nine months, the lawyer said.

The vaccination effort, according to allegations in a report filed with a Pakistani appeals court, was meant to collect bin Laden's DNA so the CIA could compare it with samples of bin Laden family DNA it already had, but no one at his Abbottabad compound agreed to be vaccinated.

The report alleged that Afridi admitted receiving $75,800 from handlers for the vaccination effort.

In 2012, senior U.S. officials told CNN that Afridi worked with the United States prior to the bin Laden raid, but was never asked to spy on Pakistan and was asked only to help locate al Qaeda terrorists posing a threat to both Pakistan and the United States.

After Afridi's conviction, then-U.S. Secretary of State Hillary Clinton and then-U.S. Defense Secretary Leon Panetta called for his release. Clinton said Afridi "was instrumental in taking down one of the world's most notorious murderers."

CNN's Reza Sayah, Elise Labott and Jason Hanna, and journalist Annabel Symington contributed to this report.