Former MMA star Mark Hunt has revealed he asked Paul Gallen if he was taking performance enhancing drugs ahead of their fight on December 16, per Fox Sports.

As part of the card for Tim Tszyu's fight with Bowyn Morgan at Bankwest Stadium, Hunt and Gallen will pull on the gloves for a highly-anticipated fight.

Hunt admitted he held some concerns surrounding Gallen's past with Cronulla's peptides scandal, although the NRL great has denied any misconduct of the sort.

The Auckland-born fighter has been a long advocate of keeping combat sports clean of drugs, with Hunt still chasing US$2.5 million from Brock Lesnar after he lost to the former WWE star, who had tested positive to clomiphene.

Speaking on the Standing Eight podcast, Hunt revealed he messaged Gallen to make sure the Cronulla legend would be clean.

“I messaged Paul about that,” he said.

“He called me and said his arm popped. I’m thinking if it has torn off the bone, he’s going to be out for about a year. He called me a few days later and said the fight’s on again.

“I thought how’s that true? You’ve got to have an operation, it’s nine months (out) straight away.

“And I messaged him: are you taking steroids? Are you cheating? He messaged back and said no.

“It’s already in my contract. With the UFC, I’ve put a lawsuit forward because of that and the unfair advantage they get. It’s like pushing a wheelbarrow full of s**t up the mountain.”

Hunt lauded Gallen's ability and said he'd be prepared to fight anyone following their bout next month.

“Paul is a very interesting person, he’s no slouch, he’s a great fighter,” Hunt added.

“I’d fight anyone, I’d fight underwater. I’m a prize fighter. I’m not here to f*** around getting punched in the head. I fight to eat.

“This fight is not about whether I can cut it, it’s about whether Paul can cut it with the best. I’m not the best boxer, but I’ve been a martial artist for a long time.

“Not to be rude to the other guys he’s fought, I'm not sure they’ve run the gauntlet like I have. It’s not on me to prove anything here, it’s on Paul to show he can cut it with the best in the world.”