The Afghan Taliban have confirmed covering up the death of their previous leader, Mullah Omar, for more than two years.
Omar's death was kept secret by some Taliban leaders, due to tactical reasons.
It was claimed by Afghan intelligence that he had died in 2013, in a hospital in Pakistan.
The reasons behind the cover-up were made clear in the biography of the new Taliban chief Mullah Akhtar Mansour, who was a longtime deputy of Omar and has been selected as the man to lead the militant group by senior members of the Taliban.
“Several key members of the supreme leading council of the Taliban and authentic religious scholars together decided on concealing the tragic news of passing away of (Omar)… and keep this secret limited to the very few colleagues who were already informed of this incorrigible loss,” according to the biography.
The cause of Mullah Omar's death is still unknown and the biography gave no information about how he might have died.
"One of the main reasons was the fact that 2013 was considered the final year of power testing between the mujahidin and foreign invaders." the group said in a document.
Although 13,000-strong US-led force remains in the country for training and counter-terrorism operations, NATO troops ended their combat operations in Afghanistan last December.
After the confirmation of Omar’s death and Mansour’s ascension, observers claimed that the move will cause a split within the militant group. As Omar’s brother and son, also some of the top leaders in the group, have declined to pledge allegiance to Mansour, saying selection process was biased and had happened too quickly.
The Taliban have suffered a string of defections to ISIS militants. Observers said, Omar was seen as an unifying leader and also with Omar gone, more Taliban members will join rival ISIS militants who are making forays into Afghanistan.
Mullah Omar fought Russian forces from 1983 to 1991, losing his right eye. The militant, became Afghan