Chechen separatist rebel leader Abdul-Khalim Saydullayev has been killed in a police operation, Russian and pro-Moscow Chechen sources say.
Abdul-Khalim Saydullayev was not a familiar figure
He died in a gun battle in his home town, Argun, along with a Russian federal agent and a policeman, Russia's intelligence service says.
No comment from the rebels was immediately available.
Mr Saydullayev was appointed in 2005 to replace Aslan Maskhadov after the rebel president died in a Russian attack.
Chechen Prime Minister Ramzan Kadyrov welcomed the news as "a severe blow" to the separatists.
"The terrorists have been virtually beheaded... and they are never going to recover from it," he told Russian news agencies.
Argun's chief of police, Ali Tagirov, told Russian media the body had been identified by people who knew Mr Saydullayev and there was "no doubt" about his identity.
CHECHEN REBEL PRESIDENTS
Abdul-Khalim Saydullayev: reportedly killed by police in Chechnya in June 2006
Aslan Maskhadov: killed in Russian army operation in Chechnya in March 2005
Zelimkhan Yandarbiyev: killed by a car bomb in Qatar in February 2004 - Russia denied allegations of its involvement
Dzhokhar Dudayev: killed by air-launched Russian missiles in April 1996
Nikolai Patrushev, head of Russia's FSB intelligence agency, confirmed that an FSB agent and a local policeman had also been killed.
A gun battle erupted at 1100 (0700 GMT) on Saturday when police launched their operation, he said.
According to one Russian media report, Mr Saydullayev had been discovered in a house with three or four other rebels.
The NTV report added that another Chechen militant was also killed while two escaped.
Though he was appointed president, he was a relatively obscure figure, correspondents say.
He used to make religious programmes for the separatists' TV station and speeches he released as leader are couched in Islamist language.
He was much less prominent than veteran separatist commander Shamil Basayev who appeared on a rebel website last week in what was billed as a new video.