ISLAMABAD: Pakistan and Afghanistan are in talks on the release of a key member of the Taliban, whose 2010 arrest in Pakistan was blamed for sabotaging peace initiatives, a Pakistani foreign ministry official confirmed Friday.

Mullah Abdul Ghani Baradar, a powerful Taliban military chief who has been described as the militia's second in command, was arrested in Pakistan's port city of Karachi.

The Afghan government and the former UN envoy to Afghanistan said his detention had adversely affected efforts to talk to the insurgents.

“The issue of prisoners is under discussion between the two countries,” foreign ministry spokesman Moazzam Ahmad Khan told reporters when asked to comment on Afghan demands for access to Baradar and for his release.

The spokesman did not name any prisoner or give further details, but when asked, confirmed that Baradar was still in Pakistani custody.

A senior security official told AFP that no agreement had been reached to release Mullah Baradar.

“Pakistan may give Afghan officials an access to Mullah Baradar but no deal is being made as such” to release him, he said on condition of anonymity.

Baradar is the most important Taliban leader to be captured since the 2001 US-led invasion ousted the Afghan militia from power in Kabul.

He was known as a trusted aide to the Taliban's elusive leader Mullah Mohammad Omar. Shortly after Baradar's arrest, the Pentagon said two other Taliban officials were arrested, also understood to have been captured in Pakistan.

In March 2010, Kai Eide, the then just retired UN envoy to Afghanistan, said the arrest of key Taliban in Pakistan had stopped a secret channel of communication between the insurgents and the United Nations.

Afghan President Hamid Karzai has repeatedly invited the Taliban to open direct talks with his government and on Pakistan to facilitate an end to the 10-year war.

Pakistan has said it will do anything required by Kabul to support an Afghan-led peace process, but there is a wide degree of scepticism in Afghanistan and the United States about the sincerity of the former Taliban ally.