Earlier this month, it was reported that Canelo Alvarez tested positive for the banned substance clenbuterol in two urine samples on February 17 and February 20. Alvarez, who is set for a rematch against Gennady Golovkin in May, blamed contaminated Mexican meat for the traces of clenbuterol, but Golovkin isn't buying it.

According to ESPN, GGG spoke with reporters at his training camp in Big Bear Lake, California last night and accused Alvarez of knowingly cheating.

"Again with Mexican meat? Come on," Golovkin 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.

"This guy, he knows. This is not his first day in boxing. He proves he gets benefits from everyone and he can get away with it. Check him on a lie detector and then we can find out everything."

Additionally, Golovkin called out Oscar De La Hoya, who is Alvarez's promoter. "It was pretty obvious when [Alvarez's] muscles were all [enlarged] ... and with the traces of injections, which were visible," Golovkin said, per ESPN. "Before the first fight, I knew he was not clean. I can talk about Oscar De La Hoya too. He is also not clean. He's dirty."

The first match between Alvarez and GGG last September ended in a draw after one judge scored it 118-110 for Canelo, a second judge had it 115-113 for Golovkin and the third had it even.

Despite Alvarez's failed test, the rematch is still on for May 5 at the T-Mobile Arena in Las Vegas.