For the second time in four months, WBO middleweight champion Billy Joe Saunders has pulled out of a title defense against British countryman Martin Murray, only this time Murray has accused him of doing it for strategic business purposes. 

Saunders (26-0, 12 KOs), who was originally scheduled to face Murray on April 14, withdrew from their June 23 date on Sunday due to an undisclosed injury. 

The veteran Murray (36-4-1), 35, took to social media and outright accused Saunders, 28, of withdrawing so he could be ready to face either unified middleweight titleholder Gennady Golovkin or lineal champion Canelo Alvarez should their possible September rematch fall apart on the negotiation table. 

"Just think it's better you hear it from me rather than another bulls--- story, but the fight's off with Billy Joe Saunders," Murray said. "He's s--- out again. The first time was his hand, now it's his hamstring. We know that he's just trying to make a big money fight with Golovkin or Canelo and I'm too risky to fight. He just doesn't want to fight me." 

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The June 23 card at the O2 Arena in London will still go on as planned, according Monday's announcement from promoter Frank Warren, and will feature a number of young English prospects including heavyweight Daniel Dubois. Although Murray, who previously was unsuccessful in three world title fights, may stay on the card against a late replacement, Warren spoke out against his claims that Saunders is faking.

"I've seen rumors that Billy isn't injured, but he is a fighting man and there's no way he would pull out unless he had to," Warren said. "It's a shame after the devastating performance against [David] Lemieux last Christmas, as this was a chance for Billy to keep momentum as we continue to chase big fights for him. Martin may still feature on the card and we are working day and night trying to put something together. We will let the fans know news on this when we've had a chance to look at all options."

Murray came back on Instagram on Monday by calling out Saunders for posting a 2013 tweet in which Saunders insulted David Haye for pulling out of a fight against Tyson Fury. 

"It wasn't acceptable when it was happening to someone he knew but now he's doing it he thinks it's OK," Murray said. "He's an hypocrite with double standards and is an imposter!

"You wouldn't hear the last of it if something like this happened to him and he's just like a typical bully who only fights and tries to intimidate people he knows he can win. The sooner people realize that he won't fight the likes of Golovkin or Canelo the better."

Although Saunders formally apologized to Murray a second time in Warren's news release on Monday, saying "I am hugely sorry that I've let both him and the fans down and prevented a great fight from happening," he was far less pleasant in a video posted Monday on social media. 

"I see you put that I'm a s---house and this and that on your Instagram," Saunders said. "Who the f--- has got their s---house from you? What you are is a bum. You are a tick over fight for me. You were never dangerous. You were played to eat the jab and you would've got beat comfortable. 

"I understand that you got frustrated because you wanted your paycheck before you gave up and retired because you've got family. But there's one thing here Martin Murray, if I'm a s---house than I'll be in Manchester on Saturday. Walk to my face and say that and I will lay you cold out on the floor. I don't give a f--- where they are from or who they are from, I will fight any man born from his mother." 

Saunders went on to call himself a "clever business man," and closed by calling Murray nothing but "a bum who takes chances in desperate needs."