By Vadim Pushkin

According to overseas sources, veteran promoter Don King is preparing to gain a measure of revenge by filing a lawsuit against his promotional rival Andrei Ryabinsky of Russia.

Back in April of 2014, King's fighter Guillermo Jones was scheduled to face Ryabinsky's fighter, Denis Lebedev, in a rematch.

Just a few short hours before the fighters were scheduled to enter the ring in Moscow, the promoters received information that Jones had tested positive for a banned weight-cutting agent. Lebedev refused to go forward with the fight and their main event was canceled.

It was the second time that Jones had tested positive for the same banned substance. He was popped the first time after his 2013 knockout win over Lebedev.

In May of 2014, Ryabinsky filed a lawsuit against King to recover monetary damages from the canceled main event - as Ryabinsky was forced to issue refunds to the entire sold-out venue .

A Manhattan federal judge sided with Ryabinsky and awarded him $1.6 million. The amount issued was for arranging the fight, fees, advertising, equipment installation and $800,000 that King was paid as a guarantee of Jones’ participation.

Under the agreement, $250,000 was paid in advance, and King was supposed to receive the remaining $550,000 after the fight. Otherwise, the money would have to be returned to Ryabinsky. However, after the fight was canceled, King still sought the $550,000, insisting that the fight was canceled “for questionable reasons.”

This past Saturday, the shoe was on the other foot.

Also in Russia, King's fighter Bermane Stiverne was scheduled to face Alexander Povetkin, who is promoted by Ryabinksy, in a WBC final eliminator. A few hours before the event was scheduled to start, the World Boxing Council announced that Povetkin had tested positive for banned substance osterine - which has the same effects as anabolic steroids.

Stiverne refused to go forward with the fight after the WBC refused to sanction the contest due to Povetkin's positive test. The event was not canceled, as Johann Duhaupas stepped in as a late-replacement and was brutally knocked out in six rounds.

This marked the second time in the last seven months that Povetkin tested positive for a banned substance. Back in May, Povetkin failed a drug test just a few days before his scheduled bout with WBC heavyweight champion Deontay Wilder. The fight was ultimately canceled.

A few weeks after the canceled fight, Wilder and his promoter Lou DiBella filed a multi-million dollar lawsuit against Povetkin and Rybinsky in Manhattan federal court. Ryabinsky filed a counter-suit for defamation.