Footage of Conor McGregor sparring a world boxing champion has been leaked

Conor McGregor isn't about to dispel rumours of a mega-fight with Floyd Mayweather.

The Irishman has been teasing of possible MMA vs Boxing match-up with Mayweather in the ring since he was spectacularly pulled from the UFC 200 card. His Twitter has been a steady drip feed of suggestive tweets fanning the flames of the rumour mill - and Pretty Boy has been just as bad. https://twitter.com/SportsJOEdotie/status/732481399471509506 But this latest video of McGregor certainly won't stop tongues wagging. The Notorious stopped in at the Box n Burn gym in Santa Monica, California, run by former amateur boxing European champion Tony Jeffries. It's not secret he's working on his boxing - but a video from his trip has been leaked showing McGregor sparring with former ABU, IBF and IBO champion Chris Van Heerden. Jeffries, who won a bronze medal at the Beijing Olympics before retiring unbeaten from the pro game after hand surgery, send this tweet out bigging up McGregor's boxing skills... https://twitter.com/Tony_Jeffries/status/732652284841099265 Jeffries, who is head boxing coach for UFC heavyweight Brendan Shaub, then sent this tweet out further hyping McGregor's pugilistic prowess... https://twitter.com/Tony_Jeffries/status/732697223822118912 But this commentary of the leaked footage of McGregor sparring the welterweight Van Heerden isn't quite as complimentary. The Dubliner lands some shots, but walks onto many more in the process... https://www.youtube.com/watch?v=jaWDN_Pr4G8 Although the South African boxer spoke highly of the UFC featherweight champion's boxing ability. https://twitter.com/TheHeat001/status/732657153232666624 https://twitter.com/TheHeat001/status/732666825838755840