'Having left jail in Georgia, Chataev moved to Syria and in ISIS he is in charge of the whole Russian sector of work.'
In January, Russian secret services named him as the main recruiter of terrorists from ISIS to Russia and European countries.
Chataev
- nicknamed 'One-Armed' after he claimed one of his limbs was chopped
off in prison - fled Russia 12 years ago, and won refugee status in
Austria.
Once in Europe, he sent equipment back to the Northern Caucuses for terrorists to use, it has been reported.
In
2008, he was arrested in Sweden for illegal possession of arms,
spending a year in prison after Kalashnikov guns, explosives and bullets
were found in his car.
'One-Armed' insisted that he was trapped in a sting operation.
After
he completed his sentence, he moved to the Ukraine, where he was
arrested on a warrant from Russian police - but used his Austrian
refugee status to avoid deportation.
Twelve
months after that, he was found in Georgia, in the Lopota mountain
valley following a battle between police and rebels which saw three
policeman and 11 rebels killed.
Chataev was injured and later detained - but said he had nothing to do with it.
Chataev
is also said to have led Chechen Islamist Doku Umarov's armed
underground movement of Northern Caucasus from Turkey - perfectly
placing him to plan an attack like Tuesday's.
In
January, Kremlin-friendly Kommersant newspaper reported that Chataev
was 'training executors for acts of terror not only in Russia but also
in Western Europe'.
Andrey
Przhezdomsky, the advisor to the chairman of the Russian National
Anti-terrorism Committee, claimed he is at the head of a special ISIS
unit now in charge of arranging blasts in Russian and Europe.
'It mainly consists of Northern Caucasus people and there are ex-officers of the Iraq army among its trainers,' he said.
The North Caucus includes Chechnya and Dagestan, where two of Tuesday's killers are said to have been born.
The claims about Chataev's role came after the detention in Turkey last year of Yakub Ibragimov and Abdulla Abdullaev.
They
allegedly admitted to recruiting young Russians via social media,
providing them with fake passports, and taking them to ISIS camps where
they underwent training organised by Chataev's team.
Daily Mail UK