The Afghan government is investigating new reports that Taliban leader Mullah Omar has died, a spokesman said.
The Taliban has yet to comment on the claim, which was made by top sources within the Afghan administration and intelligence agency.
The sources said the reclusive militant leader had died two to three years ago.
The latest claims of Mullah Omar's death are being taken more seriously than previous such reports. The Taliban is expected to issue a statement soon.
A spokesman for Afghan President Ashraf Ghani said on Wednesday that the authorities were trying to verify the reports.
"As soon as we get any more authentication… we're going to let the media and the people of Afghanistan know about that," Sayed Zafar Hashemi said.
The Afghan government, elected last year, has embarked on a peace process with the Taliban.
A security official in Pakistan, the country hosting the talks, told the Associated Press news agency that the claims of Mullah Omar's death were mere "speculation", designed to destabilise the negotiations.
Taliban spokesman Qari Yousef Ahmadi, quoted by Sky News, said that Mullah Omar was "still alive and leading the movement". READ MORE OF THIS STORY