Conor McGregor's brief boxing career saw him well beaten by Floyd Mayweather in August 2017 in the second-richest fight in the history of the sport.As he prepared for his venture into the ring, swapping from his highly successful career in UFC, McGregor enlisted the help of Paulie Malignaggi to put him through his paces ahead of his bout against the American great.The pair sparred for the months leading up to the fight two years ago, but the two have become embroiled in a war of words ever since.It all began when the outspoken McGregor released footage which appeared to show him knocking Malignaggi to the canvas during one of the sparring sessions.The American later denied McGregor's video claims, but there has been more fuel added to the ever-increasing fire in recent days as the dispute continues.

Malignaggi was filmed slapping Artem Lobov, a long-term team-mate and friend of McGregor at a media day on Tuesday, and he was soon faced with a backlash on social media.

Malignaggi and Lobov are reportedly due to face one another in a potential bare-knuckle clash later in the summer.

The fighters both signed up to the Bare Knuckle Fighting Championship promotion prior to their showdown later this year.

And in a show of defiance and support to Lobov, McGregor used his Twitter account to post 21 images of him punching Malignaggi, who looked battered and bruised in the corner.

Here are some of the best photos:

Both men have not held back since their ill-fated sparring sessions together.

McGregor previously announced his retirement from the octagon, but Dana White, the president of UFC, is likely to hold talks with him in the coming weeks about a return in the near future.

White said recently: "I think that there’s some things that Conor wants and I think that Conor wants to get together face to face, he and I, and we probably will in the next couple of weeks and we’ll get this thing figured out."