According to MMA Junkie:
Following a UFC 120 preliminary card loss to Rob Broughton, Brazilian heavyweight Vinicius Queiroz tested positive for the banned substance Stanozolol.
UFC’s Vice President of Regulatory Affairs, Marc Ratner confirmed the findings today.
According to the UFC’s U.K. president, Marshall Zelaznik, Quieroz forfeited an undisclosed discretionary bonus from the UFC and has also been released from the promotion. The UFC will also relay the findings to the Nevada State Athletic Commission, which could affect Quieroz’s ability to gain a license to fight in the U.S.