By Hamid Shalizi and Dylan Welch
KABUL (Reuters) - Afghanistan will demand an explanation from Pakistan on the whereabouts of a former Taliban second-in-command when the leaders of both countries meet next week to discuss how to end years of insurgency, an Afghan official said on Saturday.
The whereabouts of Mullah Baradar has been the source of intense speculation since Pakistan announced his release on September 20. Pakistani sources say he is still kept in a safe house and is closely watched by his Pakistani handlers.
Afghanistan believes Baradar, who was once a close friend of the reclusive Taliban leader Mullah Mohammad Omar, has enough clout to persuade the Taliban to make peace, but his prolonged stay in Pakistan may have marred his reputation among fighters.
"Mullah Baradar is still under strict supervision," said Aimal Faizi, a spokesman for Afghan President Hamid Karzai.
"We will be seeking an explanation from Pakistan on the whereabouts of Mullah Baradar and how Pakistan can facilitate direct talks between him and the High Peace Council."
Karzai formed the High Peace Council in 2010 to seek a negotiated end to the insurgency the Taliban have waged since being forced from power in 2001 by a U.S.-led invasion.
Faizi said Karzai would raise the issue when he meets Pakistani Prime Minister Nawaz Sharif in London next week for a summit hosted by Britain's Prime Minister David Cameron.
"The High Peace Council is in touch with Mullah Baradar's family, not himself, unfortunately," Faizi said. "This is what we are seeking. All we know is that his family members were able to contact him, but the High Peace Council itself hasn't yet reached Mullah Baradar."
Afghanistan is trying to inject life into attempts to negotiate peace as most U.S.-led NATO combat troops prepare to pull out by the end of 2014.
Baradar, who was captured in Karachi in 2010, is seen as a pragmatic negotiator who reached out to Kabul with a peace initiative before his detention.
The Afghan Taliban say Baradar effectively remains under arrest and that his health has deteriorated.
Some analysts say that Pakistan sees Baradar as a tool who could help it have a say in any future peace deal and limit rival India's influence over Afghanistan after 2014.
(Writing by Jessica Donati; Editing by Maria Golovnina and Robin Pomeroy)