Ruslan Chagaev left heavyweight titleholder Nikolai Valuev at the altar once again.
For the third time, Chagaev pulled out of a mandated rematch with Valuev on Friday -- after the fighters had already weighed in for Saturday night's fight in Helsinki, Finland, the first heavyweight title bout ever scheduled to take place in that country.
The entire card was also called off because of the cancellation of the fight.
Chagaev "was unable to fulfill the Finnish boxing federation's medical requirements," according to a statement from Valuev promoter Sauerland Event.
It has been widely reported, however, that Chagaev is infected with hepatitis B, the same reason he had to withdraw from one of the previously scheduled rematches with Valuev.
"Finnish law prevents disclosure of any further private health medical information," the statement said.
Russia's Valuev (50-1, 34 KOs) was aiming to avenge the only defeat of his professional career. Chagaev, of Uzbekistan, won a majority decision against Valuev in April 2007 to claim a title in Germany.
"I would have loved to make this fight but given those circumstances it is not possible," Valuev said.
After Chagaev (25-0-1, 17 KOs) made one defense, a decision victory against Matt Skelton in January 2008, he had two rematches scheduled with Valuev but withdrew because of various injuries and illness.
The long layoff caused the WBA to demote Chagaev to "champion in recess." Because of that status, Chagaev had to fight Valuev by the end of June.
Valuev outpointed former-titleholder John Ruiz for the vacant belt in August 2008.
Valuev claimed a controversial decision against Evander Holyfield to retain the belt in December, and, after Chagaev was medically cleared to fight, he won a six-round technical decision against Carl Davis Drummond in February.
This set the stage for the third rematch when Sauerland Event won the right promote to the fight in an April purse bid, beating Chagaev promoter Universum.
Universum issued a statement claiming Chagaev was fit to fight:
"We cannot understand all this. Ruslan Chagaev is ready to box. His blood work has been stable for several years, including before this fight. The German Boxing Federation, the WBA and Dr. Walter Wagner, the doctor representing the Austrian Boxing Federation which regulates cards of Sauerland Events, have all classified him as safe. They are trying to dodge Ruslan Chagaev here by hook or by crook. We will examine this situation very closely and take any steps necessary."
Before boarding a flight from New York to Helsinki, co-promoter Don King released a statement saying the WBA should announce Valuev as its undisputed champion.
"Nikolai has been patient in waiting for Chagaev to become medically fit to fight," King said. "We applaud the WBA for making every effort to allow Chagaev to return, but it is clear now that we must move on."
It was unclear what the sanctioning body would decide.
"It's a decision that the board of the directors of the WBA has to make," WBA official George Martinez said to the Associated Press. "We will meet as soon as possible and address the problem. We have to collect all the facts and in a proper time we'll make a decision."
With former heavyweight titleholder Lamon Brewster of the United States and fringe contender Kali Meehan of Australia scheduled to box on the undercard, Sauerland Event said it tried to negotiate with both fighters to fill in for Chagaev on short notice in order to salvage the card. However, terms could not be reached with either fighter.
"Unfortunately, we have no other chance but to call the whole show off," Sauerland Event general manager Chris Meyer said. "Our top priority is Nikolai's health and it could not be guaranteed."
Dan Rafael is ESPN.com's boxing writer. The Associated Press contributed to this story.