A post-fight drug test for UFC heavyweight Lavar Johnson (17-7 MMA, 2-2 UFC), who lost a unanimous decision to Brendan Schaub (9-3 MMA, 5-3 UFC) at UFC 157, has been flagged for elevated levels of testosterone. An additional carbon isotope ratio test “confirmed the testosterone was consistent with the administration of a steroid,” according to CSAC Executive Officer Andy Foster.

MMAjunkie.com (www.mmajunkie.com) recently requested and today received testing results from the California State Athletic Commission, which also passed along word that the event’s remaining tests came back clean.

Foster clarified that the initial failure was not due to an elevated testosterone-to-epitestosterone (T/E) level, but could not provide further details on Johnson’s failure at the time of this writing.

The commission tested competitors for drugs of abuse and performance-enhancers.

UFC 157 took place Feb. 23 at Honda Center in Anaheim, Calif.

Johnson, who fought Schaub on the event’s FX-televised preliminary-card, tried in vain to keep the fight standing, but was repeatedly taken to the mat over the course of three rounds. From his back, he asked Schaub to stand with him in the final frame and was denied.

The loss was the second straight for Johnson, who opened his UFC career with knockout wins over Joey Beltran and Pat Barry.

Recently, the UFC took a hard line on failed drug tests when it released welterweight Matt Riddle following his second marijuana infraction, and Johnson’s positive test could very well jeopardize his octagon career.

For complete coverage of UFC 157, check out the UFC Events section of the site.

(Pictured: Lavar Johnson)