It was after a test on October 17 in Cali that Farah, 32, who plays with Juan Sebastian Cabal in a full-Colombian pair, got stuck. Farah claims he got the anabolic steroid via contaminated meat, the AP writes.
Farah is now suspended until further notice by the International Tennis Federation, ITF.
Farah is in Los Angeles- I will not be able to participate in the Australian Open, a tournament I have been preparing for since December. I'm in Los Angeles now, Farah writes on social media.
He and Cabal won the double in last year's Wimbledon and US Open.
Farah was tested negative two weeks earlier in Shanghai and has tested negative at least 15 times during his career.
Cabal will compete in the Australian Open with another partner.