One of the most notorious Chechen rebels, Salman Raduyev, has died in jail in Russia.

Raduyev was sentenced to life imprisonment for multiple murders and terrorism, in December, 2001.

Raduyev led one of the most powerful rebel groups

Prison officials said Raduyev died from internal bleeding at his prison in the Urals town of Solikamsk.

Russian officials denied any suggestion of foul play.

"I have already been asked today whether he was beaten, killed. But this is not even an issue," said Yuri Kalinin, deputy justice minister.

Raduyev, 35, led an infamous raid on the southern Russian republic of Dagestan in 1996, taking hundreds of people hostage at a hospital and using some as human shields.

A total of 78 people were killed in the attack.

He was captured by Russian forces in Chechnya in March, 2000, and tried in court in Dagestan.

He was the most prominent Chechen rebel to be captured by Russia in its fight against Chechen separatists.

Ruthless

During the Chechen war of 1994-1996, Raduyev controlled one of the most powerful rebel groups in the breakaway Russian republic.

But it was his daring raid on the hospital in the town of Kizlyar which earned him a reputation for ruthlessness.

Raduyev said he was taking orders from his father-in-law, the late Chechen President, Dzhokhar Dudayev, who was killed by a Russian missile in 1996.

Raduyev's unit fled Kizlyar with about 150 hostages and fought their way through Russian troops to escape back to Chechnya.

Back from the dead

In March, 1996, Raduyev was shot in the head in an assassination attempt and reported dead.

However, he reappeared four months later after treatment abroad, becoming a bitter opponent of Chechen President Aslan Maskhadov.

In 1999, Raduyev underwent major surgery to reconstruct his face, having first signed an agreement promising not to take revenge on the surgeons if the operation proved unsuccessful.

His death comes as Akhmed Zakayev, the deputy prime minister in the ousted Chechen government, faces proceedings in London to extradite him to Russia to face charges of murder and waging war.