Billy Joe Saunders fails voluntary drug test ahead of WBO middleweight title defence against Demetrius Andrade, according to reports

BILLY JOE SAUNDERS' world title defence against Demetrius Andrade is under threat with the Brit reportedly failing a drugs test.

According to ESPN, the 29-year-old has tested positive for the banned substance oxilofrine just days after being slapped with a £100,000 fine by the British Boxing Board of Control.

In response to the story, he tweeted: "some s***" to his 129,000 followers.

The WBO middleweight champion is currently preparing to fight Andrade in Boston on October 20, but could be stripped of his title if the claims prove true.

It continues an awful week for Saunders, who was heavily fined after footage showed him offering a woman £150 worth of drugs in exchange for a sex act.

While the unbeaten southpaw was handed a parking ticket yesterday to add to his recent woes.

Oxilofrine is a stimulant which is used in some supplements claiming to increase performance because of it is believed to help burn fat.

The compound has also been suggested to increase adrenaline production, endurance, and focus as well as improving oxygenation of the blood.

Sprinters Tyson Gay and Asafa Powell both tested positive for the substance in 2013.

American Gay landed a 12-month ban while Jamaica's Powell was handed an 18-month suspension.

In April, Saunders branded Canelo Alvarez a "cheat" and insisted the Mexican should never box again over a failed drug test.

He said: "I rated Canelo very highly but now he's gone down in my estimations so much. I don't rate him as a fighter at all.

"Even if he beat Golovkin (in the future), I wouldn't class him as beating him because I still look at him as a cheat.

"I don't agree with what he's done. And I think it's a disgrace for boxing.

"You get these young fighters coming up now, they're looking at Canelo, looking at what he's got and what he's become. Are they going to think 'we can do that, we can get away with a six-month ban?'

"When you see people like that enhancing their body to do more damage on someone, I think that's cheating and it should be a ban for life, most definitely."

Going even further in his criticisms , he added: “If somebody dies at the hands of a drug cheat it’s murder, 100 per cent. They’ve all got kids and families to go home to."

Under British Boxing Board of Control rules Saunders would not lose his licence as the substance is only banned in-competition and would have to be shown in his system on the day of the fight.

SunSport has contacted Frank Warren's team for comment. The Massachusetts Athletic Commission are aware of the result and are awaiting more information.