Russia's main security service claimed Thursday that Khattab, one of the leading Chechen warlords, was killed in a special operation last month.
Federal Security Service (FSB) spokesman Alexander Zdanovich was quoted by Interfax as saying that Omar Ibn al Khattab was killed by Russian troops in Chechnya. He promised to provide documentary evidence of the operation soon.
Sergei Yatstrzhembsky, chief Kremlin spokesman on Chechnya, later confirmed Zdanovich's remarks.
"There is rather weighty evidence that this odious person, one of the organizers of terrorist bands in Chechnya, has been liquidated. We hope this evidence will be provided to the public in the near future," Yastrzhemsky told the NTV television.
There were still no independent confirmations of the claim. Akhmad Kadyrov, leader of the pro-Moscow Chechen administration, voiced doubt over the FSB's claim. He said he would believe it only if he saw Khattab's body.
Khattab, a Jordanian who goes by one name, is seen by Russian authorities as one of its worst foes in the breakaway republic of Chechnya. As a veteran of the fight against the Soviet occupation of Afghanistan in the 1980s, Khattab has been active in Chechnya since the first conflict in the region in 1994-96.
He was especially notorious for an attack on a convoy of federal armored vehicles in April 1996. Fifty-three Russian servicemen were killed and 52 wounded in the attack.
The Khattab unit, which was made up of 1,500 rebels, was disciplined and capable in combat.