The 14 Afghan Taliban cadres were freed in two phases.
Nine of them were released as an 18-member Afghan High Peace Council delegation led by Salahuddin Rabbani wound up its four-day visit to Islamabad yesterday.
Four cadres were freed ahead of the Peace Council's visit as a confidence-building measure, sources told PTI.
Other than Mujahid, the cadres were all mid-level leaders of the Afghan Taliban.
Mujahid's name was on a list of Taliban cadres whose release had been sought by Afghan authorities.
Sources close to Mujahid in Peshawar too confirmed that he had been freed and had joined his family last night.
Mujahid, who is in his 40s, was appointed head of a faction of the Hezb-e-Islami after the death of his father Maulvi Younus Khalis, a well-known militant leader of eastern Afghanistan.
More From This Section
Mujahid was a member of the Afghan Taliban's military council and the head of the Tora Bora Mahaz in Afghanistan's Nangarhar province.
He was detained in Peshawar in June 2009.
The Afghan High Peace Council had asked Pakistan to free four militant commanders, including Mujahid and Mullah Baradar, the former second in command of the Afghan Taliban.
Baradar was arrested in Karachi in February 2010 and was head of political and military affairs until his arrest.
The Peace Council delegation returned to Kabul yesterday after securing the release of the Taliban cadres and a promise that the Pakistan government would consider freeing Mullah Baradar, the Dawn reported.
On the last day of the visit, Salahuddin Rabbani and his delegation pressed for the release of Mullah Baradar and at least three other key aides of Taliban chief Mullah Omar, including Mullah Noorudin Toorabi.