A lawyer for Don King said the boxing promoter plans to sue Klitchsko, alleging that the Ukrainian's claims of injury are a smokescreen, Boxingtalk.com reported.
"The fact that Klitschko was operated on by an unknown surgeon at an unknown hospital gives us a ground to accuse him of falsifying his injury. All this is a cover up to let him escape meeting Rahman in the ring," King said in a statement. "Unfortunately we cannot acquire X-rays of his heart and blood. Then everyone would understand that he does not have even a trace of courage."
On Wednesday, Klitschko, the current WBC champion, announced that he would retire. He said that he had been told he needed at least six months to recover from injuries.
"I would like to end my career at the top," he said.