Jones Jr set to return

"Both sides have already signed contracts. The fight will take place in Moscow on May 22," Vladimir Khrynov was quoted as saying by Russian media.

Jones, 42, who has won eight world titles in four weight classes ranging from middleweight to heavyweight, has not fought since losing to fellow American Bernard Hopkins in a unanimous decision last April.

He was once regarded as the world's greatest pound-for-pound fighter and has a record of 54 wins, including 40 knockouts, and seven defeats.

Lebedev, who at 31 is 11 years younger than his opponent, last fought German Marco Huck for the WBO cruiserweight title in December, losing in a split decision.

It was his first defeat in 22 professional fights.