SOCHI. Sept 28 (Interfax) - Russian President Vladimir Putin said on Friday that Russian law enforcement authorities would initiate criminal procedures against Andrei Lugovoi if the United Kingdom provides evidence of his involvement in Alexander Litvinenko's murder.

"Lugovoi is a Russian citizen. If any evidence is provided of any illegal acts on his part, the Russian law enforcement system will make decisions to prosecute him, as, indeed, it would against any other person," Putin told a conference in Sochi.

"Unfortunately, the demands of our British partners for Lugovoi's extradition are not backed up by any documentary evidence that he has committed any kind of illegal act," the president said.

"There is only a demand for extradition and accusations but there are no documents supporting his guilt," Putin said.

"If (such documents) come are provided the Prosecutor General's Office will give them consideration and will work with its British counterparts in a constructive and active way," he said.

"If any of our partners seek to fan political passions over this case, nothing good will come out of it," Putin said.

"According to estimates by the Prosecutor General's Office, about 20 Russian citizens who, have committed serious and highly serious crimes, are hiding in Great Britain," the president said.

"Despite numerous requests for their extradition nothing has happened," he said.