ISLAMABAD -- The son-in-law of a renegade Afghan warlord wanted by the United States has been detained for questioning in Pakistan, police said on Wednesday.

Ghairat Baheer, son-in-law of warlord and former Afghan prime minister Gulbuddin Hekmatyar, was taken from his house in Islamabad early on Tuesday, a local police officer, who did not want to be identified, said.

A report in the English language newspaper, ***The News***, said agents of the U.S. Federal Bureau of Investigation took part in the raid, but the police officer said he could not confirm this, Reuters reported.

"I think his arrest is aimed at finding clues about the whereabouts of Gulbuddin Hekmatyar," ***The News*** quoted an unnamed relative of Baheer as saying.

Baheer's residence in Islamabad was locked on Wednesday. A neighbor's security guard said Baheer and all male members of the household, including his servants, were taken away.

Hekmatyar heads Afghanistan's Hezb-i-Islami faction and is wanted by the United States for his opposition to the U.S. military presence in that country.

In May, the U.S. Central Intelligence Agency, believing Hekmatyar was plotting against the U.S.-backed Afghan government of Hamid Karzai, fired a missile from an unmanned spy plane in a failed attempt to kill him.

Karzai's government has accused Hekmatyar of involvement in a car bomb attack in Kabul on September 5 that killed at least 26 people. It also blamed Afghanistan's former Taleban rulers and their Al-Qaeda allies, with whom Hekmatyar denies any connection.

About a week after the bombing, Hekmatyar expressed grief over the loss of life but reiterated a call for holy war against U.S.-led "aggressor forces".

Hekmatyar was prime minister for much of 1993 and engaged in bloody power struggles for control of Kabul in which 10,000 people were killed. He briefly served in the post again in 1996 until Kabul fell to the Taleban and he fled to Iran.

He tried unsuccessfully late last year to unite all Afghan factions, including the Taleban, against U.S. forces.

Hekmatyar was expelled from Iran earlier this year after he called for the removal of Karzai's government and U.S.-led coalition forces in Afghanistan that helped oust the Taleban.

His current whereabouts are not known.

Despite being a staunch critic of Washington, Hekmatyar received significant U.S. support to fight Russians during the 1979-89 Soviet occupation of Afghanistan.