KSI’S win over Joe Fournier is allegedly in jeopardy with the Youtuber-turned-boxer at risk of being stripped of his victory.
It comes after reports that authorities are set to review a clip that appears to show his knockout came via an illegal elbow.
KSI defeated the businessman and professional fighter with a second-round knockout.
But the Mail claim the victory is now under review.
Fournier was under pressure from the start and KSI appeared to send him to the canvas with an amazing punch.
However, replays showed that he instead caught him with a brutal elbow.
As the clip is slowed down, many were left shocked as they saw Fournier’s eyes roll back soon after the illegal impact.
After securing his win, KSI was probed by DAZN on the elbow, but he insisted he didn’t see anything wrong.
He said: “I hit him with a massive shot and he was dazed, he was scrambling trying to hold onto me for dear life.”
But Fournier disagrees and has been left raging but could soon have his defeated overturned.
The 40-year-old told Fred Talks Fighting: “He cheated, it’s clear, you’ve all seen the replays. He hit me with a clean elbow.
“When you’re fighting the promoter on his own show – I’ve never been cheated like that.
“I can’t believe I came on this promotion to teach kids you’ve got to do the right thing, you’ve got to be ethical, you’ve got to work hard for everything you get. Not to cheat and you win.
“And furthermore the terrible sportsmanship from Alexis [KSI’s coach] coming and disrespecting me in the corner when they’ve clearly cheated after that – f***ing embarrassment.
“Embarrassment to the sport of boxing.”
KSI’s rival Jake Paul was also unhappy, saying: “I respect boxing too much to respect what that was.
“If that was indeed a real boxing match it will be ruled a no contest or disqualification.”
Fans have also questioned the victory as many took to social media, writing: “KSI shouldn’t take that win, you can’t elbow someone and knock them out in a boxing ring. Accident or not.”
Another said: “KSI bringing MMA into a boxing ring.”