Lawyers representing the Pakistani doctor jailed after helping the CIA find Osama bin Laden appealed against his conviction on Friday.
Shakeel Afridi was sentenced on May 24 to 33 years in jail under Pakistan's archaic system of tribal justice, worsening Pakistan's already precarious relationship with the the United States.
He was arrested after US troops killed bin Laden in May 2011 in the town of Abbottabad where he set up a fake vaccination programme in the hope of obtaining DNA samples to confirm the Al-Qaeda leader's presence.
But he was convicted for treason over alleged ties to Lashkar-e-Islam and not for working for the CIA, for which the court said it did not have jurisdiction.
"We have filed an appeal against his conviction and have challenged his sentence and the charges levelled against him," said Idress Kamal, who heads the Peace Movement, an anti-militancy civil society group that has taken up Afridi's case.
Kamal said the appeal was filed in a court headed by the commissioner of the northwestern city of Peshawar who hears appeals against judgements meted out under Pakistan's tribal justice system known as the Frontier Crimes Regulation.
"All the charges labelled against him were baseless. Shakeel Afridi had no links with Lashkar-e-Islam," Kamal said.
The faction, led by warlord Mangal Bagh, is widely feared for kidnappings and extortion in the tribal district of Khyber, where Afridi worked for years.
His conviction said Afridi had "close links" to the group, but the militia has denied any links with Afridi and has threatened to kill him.