UFC champion Conor McGregor has released a boxing training video of himself, fuelling further speculation that a cross-sport showdown between himself and Floyd Mayweather is now in the pipeline.

Talk of a possible fight with Mayweather, a five-weight world champion, took off late last year after the Irishman secured a boxing licence in California, enabling him to train and fight in the US state.

More recently, McGregor emphasised his desire to face the American, insisting it was a 'fight he wanted' to happen.

Speaking in the wake of Leo Santa Cruz's victory against Carl Frampton on 28 January, the reining UFC lightweight champion said: “That fight is more than just being explored. That fight has been in the works a while now.

"Look, there’s a lot of steps to get through to get the fight going, but it’s the fight to make. It’s the fight the people want. It’s the fight I want. I know I’m confident going in there.

“I’ve got the reach. I’ve got youth. I’ve got the confidence. I’ve got the unpredictable style. You can’t prepare for a style like me. A guy said to me, why conquer one world when you can conquer two? So I’m going to go conquer two worlds.”

In his latest Instagram video, which has amassed more than 1.5m views, the 28-year-old can be seen sparring at SBG Ireland, a mixed martial arts academy and professional team based in Dublin.

In anticipation of what would be the most lucrative contest in combat sports history, McGregor is clearly taking the challenge of Mayweather seriously as he bids to prove himself in the ring.

Mayweather retired from boxing in 2015 with a perfect professional record of 49-0, equaling the record of all-time great Rocky Marciano, and 'Money' has since insisted that there is only one bout that would motivate him to dust off his old gloves.

"Most likely the fight between me and Conor McGregor will happen," Mayweather said last month.

"That's the only fight that will get me back in the ring. He's going to do a job on his side and we are going to do a job on my side and hopefully all the fans in the UK come over and support me.

"I don't know (when it will be), I need to communicate with my team, the fight hasn't been made yet, but it is all about entertainment so hopefully we can make it happen."