Canelo Alvarez, left, and Gennady Golovkin pose during a weigh-in in Las Vegas last September. (John Locher/Associated Press)

In a sport that long ago ran out of eyes to blacken, boxing’s much-anticipated rematch between Canelo Alvarez and Gennady Golovkin was canceled Tuesday after fight organizers determined Alvarez, beset by a pair of failed drug tests, wouldn’t likely be cleared in time to step into the ring on May 5.

The announcement was made at a news conference in Los Angeles, where Alvarez repeatedly said his ingestion of the performance-enhancing drug Clenbuterol was accidental, the result of contaminated meat he ate while training in his hometown of Guadalajara, Mexico. A pair of positive tests in February had triggered an independent investigation by the Nevada State Athletic Commission, which has scheduled a hearing for April 18.

“It’s extremely unlikely that this matter is going to get resolved by then properly,” said Eric Gomez, president of Golden Boy, Alvarez’s longtime promoter.

Alvarez said he’s still eager to step into ring again with Golovkin. His camp said it hopes the commission will clear him to fight by the summer and suggested the rematch could perhaps be staged in August or September.

“Absolutely, that’s the fight I want,” Alvarez said. “That’s the fight I want to give the fans.”

Golovkin has expressed frustration with the unexpected controversy but never stopped training. He learned on Monday that Alvarez was pulling out of the rematch, according to his promoter.

“Everyone was looking forward to it, especially GGG,” Tom Loeffler said in a phone interview. “He felt he won the first fight and felt wronged by the decision. So he was looking forward to getting Canelo back into the ring to prove that he’s the best middleweight champion in the world. So clearly a lot of disappointment on our side.”

Loeffler said despite complications that effectively made the initial fight a two-year negotiation and now the bad drug test from Alvarez, his fighter is still eager to get in the ring.

“Both guys want the rematch,” Loeffler said. “Both guys made the biggest payday of their career the first time, so I don’t see an issue why a rematch shouldn’t take place.”

Loeffler said that Golovkin intends to keep the May 5 date at T-Mobile Arena in Las Vegas though no opponent has been lined up. Britain’s Billy Joe Saunders might have been the most logical replacement, but he’s injured and unavailable.

“It is time for less drama and more fighting,” Golovkin said in a statement.

Speaking through an interpreter, Alvarez said he was “truly shocked by what has happened” and noted several times that, “I have always been a clean fighter and I always will be a clean fighter.”

“It’s very difficult to be going through this,” said Alvarez, making his first public comments since the positive tests were announced on March 5. “I’ve always been a clean fighter. I’ve always been hard working. It’s very frustrating not being able to do more.”

Alvarez tested positive for Clenbuterol in a pair of random urine tests conducted by the Voluntary Anti-Doping Association on Feb. 17 and Feb. 20. The drug is often used to treat asthma but is banned by the World Anti-Doping Agency because it also helps burn fat and build muscle. It’s also been linked to bad beef in Mexico, where some ranchers spike their cattle feed with the drug.

While the Nevada commission investigated, the bout had been cast into doubt in recent days, following critical comments by Golovkin and the venue’s decision to offer refunds to ticket holders. Speaking to reporters last month during his training camp in Big Bear Lake, Calif., Golovkin accused Alvarez of being “dirty” before their first fight, an exciting tussle on Sept. 16 that was ruled a draw — to the frustration of many, particularly Golovkin fans.

Golovkin (37-0-1, 33 KOs) said he didn’t believe Alavarez’s tainted meat explanation was truthful.

“Again with Mexican meat? Come on,” he said. “I told you, it’s not Mexican meat. This is Canelo. This is his team. This is his promotion. … Canelo is cheating. They’re using these drugs, and everybody is just trying to pretend it’s not happening.”

Alvarez responded to Golovkin’s comments on Tuesday, dismissing the accusations and pointing to his long record of clean drug tests.

“To be honest what Golovkin or his team say doesn’t bother me at all. No. 1, they’re not doctors, they’re not experts,” he said, according to the interpreter. “I don’t pay attention to them. It sounds more to me of an excuse for not wanting to fight, that he’s scared, to be honest.”

Alvarez (49-1-2, 34 KOs) and his promoter say the fighter had never before failed a drug test and had been subject to increased testing the past several weeks with no red flags.

“I sincerely hope that given his unblemished record of having never tested positive in more than 90 tests in and out of competition with more than 52 processional fights, you would be willing to give Canelo fair consideration,” Oscar De La Hoya, Golden Boy’s CEO, said Tuesday.

Citing the pending investigation, Alvarez’s camp declined to discuss some of the specifics surrounding the positive tests. But his lawyer said they have shared restaurant receipts with investigators that show what Alvarez ate and when, and they say the drug levels are consistent with meat contamination.

Dr. Miguel Ángel Nazul, the vice president of the Mexican Federation in Sports Medicine, spoke at Golden Boy’s news conference to explain the issue Mexico has with contaminated meat and the wide-reaching repercussions, a problem that has ensnared dozens of athletes, including soccer players, cyclists and UFC fighters.

“It’s very important to clarify that for a boxer — in this case, three months before [the bout], the levels of 0.6 milligrams have no benefit for a fighter,” he said.