Floyd Mayweather and Conor McGregor are trolling each other on Instagram, and their latest posts asked fans to get involved

Photo by Reuters - Steve Marcus

Mayweather and McGregor in the build-up to their 2017 fight in Las Vegas.

• Floyd Mayweather and Conor McGregor have reignited their war of words on social media - and have even asked fans to get involved.
• Mayweather beat McGregor in a boxing rules contest in Las Vegas two years ago, however the pair have ever since been tangled in an online bout.
• Both retired fighters posted photos of their 2017 fight while asking their millions of followers to "caption" the snaps.
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Floyd Mayweather and Conor McGregor have reignited their long-standing feud, with the retired pair even encouraging fans to get involved in their war of words on Instagram.

McGregor caused controversy in the build-up to their 2017 fight in Las Vegas with a number of racially-charged comments, including that he was "half black from the belly button down".

And ever since Mayweather's 10th round stoppage win over the Irishman, which saw him take his professional record in the ring to 50-0, the pair have continually exchanged blows on social media, adding further fuel to a fire that hasn't yet been extinguished.

It all started when McGregor posted a photo from the 2017 bout on Friday, encouraging his 34.1 million followers to caption it.

Read more: Conor McGregor just claimed he's a billionaire in an Instagram post, but it's unlikely that's even close to being true

Mayweather took little time to fire a couple jabs of his own back, emulating McGregor's caption contest by posting two photos to his Instagram the following day.

The first was a face-off from their 2017 promotional tour, saying: "Caption this," while the second showed Mayweather landing a hefty shot to the Irishman's chin during his stoppage win, alongside the words: "Give me the best caption you can think of."

It is not the first time the rivals have been at each others throats.

In January 2018, Mayweather criticized McGregor over reports the former UFC champion had gotten into trouble with Irish gangsters, posting The Independent's headline to Instagram alongside the caption: "I already f----- you up in 2017, now they about to f--- you up in 2018. You're about to start your new year off with a bang."

Later that year, it was McGregor on the offensive as he unleashed an expletive-laden attack on Mayweather after the boxer announced he was going to fight the Japanese kickboxer Tenshin Nasukawa for his next fight, controversially comparing the event to the popular film series "Rush Hour."

It is unlikely a rematch between them both will come to light, as the first fight was such a convincing win for Mayweather, who announced his retirement after the fight.

McGregor, who most recently lost to Khabib Nurmagomedov at UFC 229 in 2018, has remained coy on when and if he is set to return to the Octagon, but UFC boss Dana White has refused to rule out a rematch between McGregor and the Russian later this year.