Anthony Joshua believes he would be forced to quit boxing if the heavyweight champion ever endured the kind of doping scandals that have engulfed Alexander Povetkin.

Povetkin’s presence as the mandatory opponent for British star Joshua at Wembley on September 22 has infuriated fans, who feel he shouldn’t be allowed back on the big stage after his drug issues.

The 38-year-old Russian tested positive for meldonium in May 2016, the same banned substance compatriot Maria Sharapova was suspended for taking.

The failed test led to his scheduled fight against Deontay Wilder being scrapped before the WBC accepted the explanation that he stopped taking the drug before it was on the banned list that year.

That wasn’t the only black mark against Povetkin and, in December 2016, he was found to have taken a banned muscle-building drug called ostarine.

He was suspended from WBC-sanctioned fights after the second failed test, but appealed and was allowed back into the sport with a year-long ban and a £188,000 ($245,000) fine.

Both fighters have signed up to the Voluntary Anti-Doping Association’s programme ahead of their Wembley date and have been tested twice.

But reigning WBA, IBF and WBO champion Joshua — who has never been linked with doping — claims a fighter of his profile would be made to pay a heavy price if he was found to be involved with substance abuse.