JON JONES faces an investigation into a potential doping offence.

Jones regained the light-heavyweight title belt with a third-round stoppage of Daniel Cormier last month but a sample tested ahead of the bout is being assessed by the US Anti-Doping Agency.

A UFC statement read: “The UFC organization was notified today (Tuesday) that the US Anti-Doping Agency (USADA) has informed Jon Jones of a potential Anti-Doping Policy violation stemming from an in-competition sample collected following his weigh-in on July 28, 2017.

“USADA, the independent administrator of the UFC Anti-Doping Policy, will handle the results management and appropriate adjudication of this case involving Jones, as it relates to the UFC Anti-Doping Policy and future UFC participation.”

UFC president Dana White admitted any lengthy ban for Jones “would probably be the end of his career”, while a statement from Jones’ manager Malki Kawa to several media outlets read: “We are all at a complete loss for words right now.

“Jon, his trainers, his nutritionists and his entire camp have worked tirelessly and meticulously the past 12 months to avoid this exact situation. We are having the samples tested again to determine the validity or source of contamination.

“Jon is crushed by this news and we are doing whatever we can as a team to support him.”

Jones became UFC’s youngest ever world champion when he beat Mauricio Rua in 2011, aged 23.

He defended the belt a record eight times, the last against Cormier, but was stripped of his title in 2015 for “violating the Athlete Code of Conduct Policy” after a hit-and-run incident which saw him sentenced to an 18-month probation order.

Two previous rematches fell through – the first after Cormier pulled out citing a foot injury, the second after Jones was suspended for a year following a failed drugs test.

He had only returned from that ban earlier in July.

Cormier, while on vacation with his family in Hawaii, released the following statement to members of the media when he heard the news.

“It’s hard to find words to describe how I’m feeling right now. I’m disappointed to hear the news. It’s very emotional. We as athletes are entitled to due process, and I will refrain from saying much more until I know exactly what happened. In my mind, on July 29, I competed and I lost. I thought Jon Jones was the better man that day. I don’t know what to think anymore. I can’t believe we are going through all of this again. We will see what happens next.”

Jones has yet to comment but his manager Malki Kawa released this statement after Tuesday’s new broke:

“We are all at a complete loss for words right now. Jon, his trainers, his nutritionists and his entire camp have worked tirelessly and meticulously the past 12 months to avoid this exact situation. We are having the samples tested again to determine the validity or source of contamination. Jon is crushed by this news and we are doing whatever we can as a team, to support him.”

UFC president Dana White described the latest turn of events as “brutal” and “unbelievable” as he addressed reporters at The Ultimate Fighter Gym in Las Vegas.

White also explained the promotion was looking into potentially booking Jones against heavyweight champion Stipe Miocic in a Dec. 2 superfight at UFC 218 in Detroit.

If it’s proven that there was no mistake and Jones did in fact take the banned substance, the UFC’s VP of athlete health and performance Jeff Novitzky said the consequences for Jones could be severe considering his history.

“Jon is afforded due process rights and those will be carried out in the coming months,” Novitzky said. “Jon definitely has one penalty under the system, so the second penalty, if it were to come to that, basically doubles the amount of the first.

So for a specified substance, which are your non-steroid substances, those would usually be a year the first time and it’s going to be two years for a second offence. The non-specified, which would be your harder substances—steroids, growth hormones, blood doping products—the first time would be two years, the second time would be potentially four years.”