The urine sample Thiago Silva submitted for testing prior to UFC 125 was "inconsistent with human urine," according to a complaint filed by the Nevada State Athletic Commission on Tuesday.
NSAC executive director Keith Kizer sent MMA Fighting an e-mail outlining the factual allegations against Silva, who now stands accused of submitting "an adulterated and/or substituted specimen for testing for the Urinalysis" prior to his decision win over Brandon Vera in Las Vegas on January 1.
Reports first began to swirl about a failed drug test when Silva was pulled from the UFC 130 card in early February. He was originally slated to face Quinton "Rampage" Jackson in that event, but was later replaced by Matt Hamill.
At the time, all the NSAC would say was that Silva's was the lone urine sample from UFC 125 that was "still processing," though the UFC's decision to remove him from his next fight was thought to be a preemptive move in anticipation of a forthcoming suspension.
Vera, who was initially released from the UFC following the loss to Silva, was later reinstated after doubts about Silva's urine sample began to emerge.
On Tuesday Kizer told MMA Fighting that the test results were the same for both urine samples submitted by Silva for UFC 125, and that the sample was found to be inconsistent with human urine after analysis done by the Sports Medicine Research and Testing Laboratory.
Silva now has 20 days from the receipt of the complaint to file an appeal, Kizer said, but the NSAC will hold a hearing on a temporary suspension for the UFC light heavyweight on April 7, 2011.
Silva's management declined to comment on this report.