Russia's federal tax body could join a $22.5 billion lawsuit filed by Russian customs against the Bank of New York if a criminal case is launched against bank's representatives, a Tax Service spokesman said Tuesday.

The Federal Customs Service on May 17 accused the bank of laundering untaxed profits of Russian exporters in 1996-99 and said it had filed a damages lawsuit with the Moscow Arbitration Court.

"The Russian Federal Tax Service will get involved only if a criminal case is launched," the spokesman said.

Andrei Belyaninov, the head of the Federal Customs Service, said earlier he was optimistic about the prospects of his service's lawsuit against the bank, and saw no reason to give it up.

Experts doubt that customs authorities will recover the entire sum claimed, but lawyers acting for the service say their claim is legitimate, as the bank has admitted that $7.5 billion was laundered, and under U.S. law the plaintiff can demand compensation three times greater than the original loss.

The bank, which pleaded guilty to violating U.S. laws on control over financial flows in 2005 and was fined $38 million, dismissed the new claim.