Editor's Note : BoxingScene writer Alexey Sukachev, who is at the venue in Moscow, said it was just announced that Jones-Lebedev was called off due to Jones' positive drug test result. The parties had a meeting and were unable to reach an agreement on the fight moving forward.

By Ben Jacobs

According to World Boxing Association Vice President Gilberto J. Mendoza, Guillermo Jones has tested positive for a banned substance ahead of his rematch tonight with Denis Lebedev for the WBA World cruiserweight title.

Mendoza wrote on his Twitter account: "Guillermo Jones tested positive in sample "A" after receiving the anti doping results from a neutral lab. The bout may happen only if the parties agree to go ahead and exonerate the WBA from any responsibility"

Both fighters are being tested by the Swiss Laboratory for Doping Analyses [LAD].

According to Panamanian journalist Juan Carlos Tapia, Jones once against tested positive for Furosemide.

Jones failed a test for the same substance after the first bout between the two men which took place in May of last year.