Another leader of Afghanistan's Taliban has been arrested in Pakistan, reports quoting Pakistani and US officials say, BBC reported.
Agha Jan Mohtasim was arrested in the southern city of Karachi, intelligence officials said.
A number of other Afghan Taliban leaders are said to have been detained recently, including the group's deputy leader Mullah Abdul Ghani Baradar.
The arrests have been hailed as a major blow to the group amid a Nato offensive against the Taliban in Afghanistan.
Analysts say that most of the information about these arrests has come from unnamed Pakistani intelligence officials, which makes it very difficult to verify.
Pakistan's Interior Minister Rehman Malik, however, did confirm the arrest of Mullah Baradar.
Agha Jan Mohtasim has been described as a possible successor to Mullah Baradar and is said to have close links to Mullah Omar, the head of the Afghan Taliban.
He was finance minister for the Taliban government when it ruled Afghanistan before being overthrown after the US-led invasion in late 2001.
Washington has been urging Pakistan to do more to act against Afghan Taliban members taking shelter in the tribal areas along the border.