Rogerio Camoes, the strength and conditioning coach for former UFC middleweight champion Anderson Silva, believes the fighter is innocent and blames a tainted supplement for his recent failed drug test.

Camoes appeared on the Brazilian TV show “Revista Combate” earlier this week to discuss Silva.

“I’ve been with Anderson for many years,” Camoes said. “When we talked the first thing he told me was ‘Master, I didn’t take anything.’ I believe and trust his word. Anderson is a very mature guy, very experienced.”

Silva was flagged by USADA just two weeks from his planned bout with Kelvin Gastelum in China at UFC Fight Night 122. Michael Bisping agreed to replace Silva, falling to Gastelum.

The test in question came in late October and marks the second time he has failed a drug test in his UFC career, with the first being in 2015 following a fight with Nick Diaz at UFC 183. That one, though, didn’t come under the current USADA-UFC partnership.

“He wouldn’t use something and risk getting suspended and getting his image tarnished,” Camoes said. “We believe in contamination of some product or supplement. All the products that he used will be analyzed so we can possibly prove there was contamination.

“The process is slow. It’s not overnight. It requires time and investment. It’s very expensive.”