Iran is secretly training Chechen rebels in sophisticated terror techniques to enable them to carry out more effective attacks against Russian forces, the Sunday Telegraph can reveal.

Teams of Chechen fighters are being trained at the Revolutionary Guards' Imam Ali training camp, located close to Tajrish Square in Teheran, according to Western intelligence reports.

In addition to receiving training in the latest terror techniques, the Chechen volunteers undergo ideological and political instruction by hardline Iranian mullahs at Qom.

The disclosure that Iran is training Chechen rebels will not go down well in Moscow, which regards itself as a close ally of the Iranian regime.

Russia has sided with Iran in the diplomatic stand-off over Teheran's controversial nuclear programme.

While the British and American governments have accused Iran of having a clandestine nuclear weapons programme, the Russians, who are building Iran's Bushehr nuclear power plant, back Teheran's claim that their nuclear intentions are solely peaceful.

Moscow has offered a face-saving formula to prevent Iran from being reported to the United Nations Security Council for its failure to co-operate fully with UN nuclear inspection teams.

Under the terms of the deal, the Russians would oversee Iran's nuclear enrichment activities to ensure that only partially enriched uranium, which is not of weapons grade, is produced.

At this weekend's meeting of the International Atomic Energy Agency in Vienna, America and Britain gave their qualified backing to the Russian proposal in the hope that it might resolve the crisis in the agency's dealings with Teheran.

But the Iranians are growing increasingly suspicious of Moscow's intentions, and it is for this reason that Western intelligence officials believe that Iran's hardline president, Mahmoud Ahmadinejad, has sanctioned the training of Chechen fighters in Teheran.

"Just as they have orchestrated attacks against British troops in Basra to pressure Britain to drop its opposition to Iran's nuclear programme, so they are trying to put pressure on Moscow by backing Chechen fighters," said a senior intelligence official.