UFC contender Sonnen fails drug test

Veteran UFC light heavyweight Chael Sonnen has failed a drug test, forcing him out of his bout with Vitor Belfort at UFC 175 in Las Vegas next month.

Sonnen says he tested positive for two banned substances last month.

The former title contender is likely to face a suspension by the Nevada Athletic Commission.

Sonnen attempted to defend himself Tuesday on Fox Sports Radio, claiming he took the banned substances as part of his move off testosterone replacement therapy, which was outlawed by Nevada regulators earlier this year.

Sonnen had an exemption allowing his steroid use, but gave up TRT after it was banned.

The 37-year-old Sonnen had lost three of his past four fights heading into his July 5 bout with Belfort, another former TRT user.