New Delhi, Aug. 11 -- KABUL - Afghanistan's Taliban government denied on Tuesday any knowledge of the whereabouts of Mahmood Shah Habibi, a United States citizen of Afghan origin who vanished from a vehicle near his home in Kabul four years ago, contradicting a public statement from the FBI that identified the Taliban's intelligence directorate as responsible for his detention.

"We have no information about Mahmoud Shah Habibi. He is not in the Islamic Emirate of Afghanistan," said Zabihullah Mujahid, spokesman for Afghanistan's supreme leader, speaking to local media. If the Taliban had known anything about Habibi's location, Mujahid said, "this issue would have been resolved long ago."

The denial came on the fourth anniversary of Habi...