The bitter rivalry between “retired” UFC star Conor McGregor and current lightweight champion Khabib Nurmagomedov got uglier as their war outside the octagon overflowed onto social media.

McGregor, in a since-deleted tweet, took a shot at Nurmagomedov’s wife Tuesday, calling her a “towel” and accompanied the insult with a picture of the couple on their wedding day and his wife in traditional Muslim garb. Nurmagomedov is a devout Muslim.

UFC'S CONOR MCGREGOR MOCKS MARK WAHLBERG, CHALLENGES ACTOR TO A FIGHT 'FOR ALL THE SHARES'

“Your wife is a towel mate,” McGregor tweeted before deleting it a few minutes later, according to TMZ Sports.

Nurmagomedov responded with a tweet with calling McGregor a “rapist” in reference to reports he was being investigated in Ireland for allegedly sexually assaulting a woman last year.

“Rapist, you are Rapist,” he tweeted. “You are a hypocrite who is not responsible for your actions. Justice will find you.”

It’s unclear who the woman in the accompanying photo is.

UFC President Dana White was forced to step in and issue a statement regarding the two combatants, according to The Washington Post.

“The ongoing situation has escalated to a level that is unacceptable. As such, we are taking the necessary steps to reach out to both athlete camps and this situation is being addressed by all parties internally,” White said.

CLICK HERE TO GET THE FOX NEWS APP

The rivalry between the two goes back before their fight at UFC 229, in which Nurmagomedov came away the victor. The two then brawled outside the octagon leading to suspensions for both fighters.