Meta founder Mark Zuckerberg is doing “serious business” in the fight game - and that’s according to Kiwi MMA star Israel Adesanya, who recently trained with the tech guru.

Adesanya shared photos online, showing himself in the gym alongside Zuckerberg and fellow UFC star Alexander Volkanovski.

A sweaty Zuckerberg showed off his honed physique in the photos, which come ahead of a rumoured fight between himself and arch-rival Elon Musk.

“No fugazi with Mark,” wrote Adensanya, also using a shark emoji.

“This is Serious Business,” he added.

TMZ reported that the pair were flown to Zuckerberg’s Northern California compound after Sunday’s UFC 290 event in Las Vegas and Zuckerberg responded to the photos on Instagram, writing: “It’s an honor to train with you guys!”

Talk of a fight between Musk, who owns Twitter, and Zuckerberg came after Musk responded to a tweet last month about the upcoming release of Meta’s Twitter rival Threads.

He took a dig about the world becoming “exclusively under Zuck’s thumb with no other options” — but then one Twitter user jokingly warned Musk of Zuckerberg’s jiu-jitsu training.

“I’m up for a cage match if he is lol,” Musk wrote.

Zuckerberg, CEO of Facebook and Instagram parent company Meta Platforms, soon responded - and appeared to agree to Musk’s proposal.

“Send me location,” Zuckerberg wrote on an Instagram story, which showed a screenshot of Musk’s tweet alongside another user’s response urging the Twitter owner to “start training”.

In response to Zuckerberg’s location request on Wednesday, Musk proposed the Vegas Octagon. He then joked about his fighting skills and workout routine, suggesting that the fight may not be serious.

“I have this great move that I call ‘The Walrus’, where I just lie on top of my opponent and do nothing,” Musk wrote.

It looks like his opponent is not joking around, however.

Meanwhile, UFC president Dana White told TMZ Sports he spoke to both billionaires and said that “both guys are absolutely dead serious about this”.

When asked why he felt that way, White said “they both said, ‘Yeah, we’ll do it’. They both want to do it”.

Whether or not Musk and Zuckerberg actually make it to the ring has yet to be seen - especially as Musk often tweets about action prematurely or without following through. But, even if their cage match agreement is all a joke, the banter gained attention.

Fans also responded quickly to Adesanya’s photos, backing Zuckerberg.

“If Zuck’s training with The Last Style Bender then it’s actually over…” wrote one.

Another offered more prosaic advice.

“Elon, run.”

- Additional reporting, AP