The top Taliban military commander, Mullah Abdul Ghani Baradar, has been captured in Pakistan, US officials say, BBC reported.
Mullah Baradar - the Taliban's overall number two - was captured in a secret US-Pakistani raid in Karachi several days ago, The New York Times reported.
Senior officials later confirmed the report, saying Mullah Baradar was "providing intelligence".
"This operation was an enormous success," one official told US network ABC News. "It is a very big deal."
Senior intelligence officials voiced hope that Mullah Baradar would provide the location of Taliban leader Mullah Muhammad Omar.
Mullah Baradar is reported to be the Taliban's most senior figure behind the reclusive Mullah Omar, who has been hiding from Western agencies since the 9/11 terror attacks in 2001.
His capture comes as Nato and Afghan troops are leading a major offensive against Taliban militants in southern Afghanistan.
The New York Times said the raid was conducted by Pakistan's Directorate for Inter-Services Intelligence (ISI) and CIA operatives, citing officials.
The newspaper said it learned of the operation on Thursday, but delayed reporting it after a request by White House officials who said disclosing it would end a very successful intelligence drive.
US officials later acknowledged the news, acknowledging it was becoming broadly known in the region.
According to Interpol, Mullah Baradar was born in 1968, and served as deputy minister of defence for the Taliban regime in Afghanistan that was toppled in 2001.
He has been subject to UN sanctions, which include a travel ban, an arms embargo and the freezing of assets.
Taliban military chief Mullah Baradar in custody
The top Taliban military commander, Mullah Abdul Ghani Baradar, has been captured in Pakistan, US officials say.