Frank Warren, promoter for heavyweight contender Daniel Dubois, is planning to protest the outcome of his boxer's world title fight with Oleksandr Usyk.

On Saturday night in Poland, Usyk knocked out Dubois in the ninth round to retain the WBO, IBF, IBO, WBA world titles.

Dubois, the WBA's "regular" champion, was the mandatory challenger under the sanctioning body.

There is a lot of controversy over the fifth round.

During the action in the fifth, Dubois landed a hard shot to the body - which sent Usyk down in pain for several minutes. The referee, Luis Pabon, ruled the shot as a low blow.

After several replays of the shot, there were many observers who felt Dubois had connected with legal blow or a borderline punch.

Usyk was eventually able to recover and dropped Dubois with a combination of punches in the eight round. The end would come in the ninth, when a right hand put Dubois down for the full count.

Warren wants the WBA to declare the fight a no-contest - as he believes his boxer was robbed of a knockout victory.

“The situation is that we will be lobbying the WBA to declare this as a no-contest. The knockdown which the referee said was below the belt… the punch actually landed on the waistband of his shorts," Warren said.

“The criteria, as is explained at the rules meeting, waist is the mid-point of your hips. So it’s much lower. That was a legitimate blow and (the fight) should’ve been stopped. He got three minutes and 46 seconds recovery time, which was wrong. He got it wrong the referee and I still don’t understand, if it was a low blow, why he didn’t take any points off him.

“I don’t think (the referee’s) crooked, I think he just got it totally wrong. As a result, it should be declared a no contest in the worst case, or a rematch ordered.”