An Afghan Taliban faction group that opposed Mullah Akhtar Mohammad Mansour as Mullah Omar's successor has elected their new leader, who the dissident faction says, was a close aid of late supreme leader of Taliban.

The splinter group announced Monday that Mullah Mohammad Rasool Akhund – who refused to pledge allegiance to Mansour – is their new leader, causing deep divisions in the insurgency.

However there is no immediate response from the Afghan Taliban to either confirm or reject the announcement – which is believed to be the first public and official division of the group.

The division emerged when the death of Mullah Omar was revealed this year in July. The news came two years late the death of Mullah Omar – which was hidden from many high-ranking Taliban members.

"We tried our level best to save the Taliban movement from disintegration but after Mansoor's refusal to step down ... we finally parted ways with him and chose our own emir," NBC News quoted a senior member of the rival faction as saying.

"Akhund is our new emir. He will now lead the Mujahideen to continue their fight against the U.S.-led foreign forces and the Afghan security troops," the source told NBC News.

The Afghan government however denied commenting in this regard.

The 50-yeard-old Akhund hails from the birthplace of the Afghan Taliban in Kandahar province, according to the source.

Another member of the faction told NBC News that their new leader was an "old and trusted friend" of the late Mullah Omar.

"He spent 10 years with Mullah Omar... and remained close to him even after the fall of Taliban regime," the source said.

Akhund repeatedly served as Taliban's shadow governor for Nimroz and Farah provinces after the group was ousted in 2001.