IBF world featherweight king Lee Selby has called for lifetime bans for fighters found guilty of doping.

News broke on Thursday that Lucien Bute had failed a drug test carried out after last month’s majority draw with WBC super-middleweight title-holder Badou Jack.

That came less than a fortnight after Alexander Povetkin's WBC heavyweight title fight with champion Deontay Wilder was cancelled when the Russian tested positive for banned substance meldonium.

Lee, who with his younger sibling Andrew is trained by Tony Borg at St Joseph’s Boxing Club in Newport, even suspects he has fought an opponent guilty of taking performance-enhancing drugs, and he believes the sport’s authorities need to be ruthless.

"If you get caught taking performance-enhancing drugs you should get a life ban," said Lee, 29. "Someone can get hurt.

"It's not like it's weightlifting; you're punching each other in the head, it's dangerous.

"It's coming out more at the moment. Maybe the testing's getting better. A lot more people are getting caught.

“You shouldn't have a loss on your record if an opponent's been found taking drugs.”

He added: "I'm on a scheme where I have to give an hour time slot every day (to be tested).

“If I sleep elsewhere I've got to update my profile, let them know where I'm staying.

“If I didn't give them the information, that comes up as a strike, and if you get three strikes you can get a two-year ban.

"I've got to give them at least three days a week when I'm going to be at the gym.

"I like the system, but they should be doing it to more people, not just individuals like myself."

Lee then explained he remained suspicious of an unnamed past opponent, saying: "When he was a younger, fitter guy, he wasn't in that type of shape."

Andrew says he has reduced his intake of supplements to just vitamin C through fears he may unknowingly consume a banned substance.

Among Andrew's team-mates at London 2012 was Nicola Adams, who yesterday won a gold medal at the AIBA World Championships in Kazakhstan, adding to her previous golds at the Olympics, Commonwealth Games and European Championships.

"It's unbelievable," said 27-year-old Andrew. "She's added this gold to every single medal: worlds, Olympics, European.

“I sparred her when I was on Team GB; she's a very tricky opponent, she'd catch me.

"She's our best ever amateur, her record says it all, and she's a role model to other girls who want to fight."