The California State Athletic Commission indefinitely suspended mixed martial artist Chael Sonnen's license to fight in the state pending a May 18 special hearing in Los Angeles.

CSAC executive officer George Dodd said the action was taken because the panel's legal counsel felt Sonnen may have perjured himself during testimony at an appeal hearing in December related to his ban for elevated levels of testosterone, which at 16.9 was four times higher than the state's allowable testosterone-to-epitestosterone ratio.

The suspension, issued two weeks ago by the CSAC, puts Sonnen on the national database used by regulators to monitor medical and administrative bans, and asks North American regulatory bodies to contact California before issuing the UFC middleweight contender a license to compete, corner, promote or act as a manager.

Sonnen claimed the testosterone in his system after his fifth-round submission loss to UFC middleweight champion Anderson Silva on Aug. 7 was a consequence of the prescribed testosterone injections he receives in treatment of hypogonadism, a condition in which the body cannot produce normal levels of the hormone.

During his pre-fight urine collection, Sonnen verbally indicated to Dodd that he felt he might test positive because he was taking testosterone. Sonnen, at Dodd's request, also wrote on forms related to his urine collection that he was injecting testosterone.

However, the revelation failed to comply with standards put in place by the state as it pertains to notification of prescribed medication. Sonnen's failure to properly notify the commission was the focus of Sonnen's appeal, which after two and a half hours worth of testimony in Sacramento resulted in a 3-1 vote to reduce his suspension from one year to six months. The suspension ended in March.

Sonnen did not verbalize the prescription or indicate it on his medical paperwork while being examined by the commission's state-licensed physician two days prior to the fight, as he should have based on CSAC protocol.

Sonnen said he did not do so in part because Nevada State Athletic Commission executive director Keith Kizer was aware of the prescribed testosterone treatment and approved it as part of that state's therapeutic use exemption program. Kizer immediately denied ever having conversations with the fighter, and specifically said a discussion involving steroids and therapeutic use exemptions did not take place. Sonnen, Kizer countered, has not been issued a therapeutic use exemption in Nevada.

Sonnen has since amended his statements to suggest that he misspoke about conversations with Kizer, and that it was his management that approached the executive director. Asked if Sonnen's management sought a therapeutic use exemption for prescribed testosterone on the fighter's behalf, Kizer simply told ESPN.com, "no."

"My commission is concerned with that because if one commission approves [the use of prescribed medication], it could sway how the vote would have come out," Dodd said. "They're looking at that allegation."

Sonnen's mention to the inspector and later to Dodd, as well as affirming his use of testosterone in writing during the urine collection one day prior to challenging Silva for the UFC belt in Oakland, Calif., are the only documented instances that he or his representatives disclosed the twice-weekly treatments to regulators since it apparently began in February 2008 under the supervision of Mark Czarnecki, a doctor of osteopathic medicine licensed in Washington and Oregon, based on reporting by ESPN.com.

Officials in California and Nevada denied having any prior knowledge of Sonnen's testosterone use. Records related to such disclosures, if they ever existed, were not found. Florida, which hosted Sonnen's fight with Paulo Fiho in November 2008, could not respond to questions regarding medical information related to Sonnen as part of its licensing process. However, as with each of his drug screenings prior to the Silva bout, Florida confirmed Sonnen's urinalysis for that fight was clean of performance-enhancing drugs.

In 2009, Sonnen fought Demian Maia in London, England. With the UFC acting as its own regulator, drug testing was conducted through a laboratory the organization hired. Marc Ratner, head of regulatory affairs for the UFC, said that he "had no knowledge whatsover" of Sonnen's prescribed testosterone until the positive test in California in 2010. Ratner, the former head of the Nevada State Athletic Commission, said if a fighter was under the treatment of prescribed medication he would have been informed. Ratner claimed he did not clear Sonnen to compete with a therapeutic use exemption.

According to testimony, Dr. Jeff Davidson, a physician hired by the UFC, was aware of Sonnen's use leading up to the August fight with Silva. Davidson asserted in a written declaration to the CSAC that he never informed regulators.

The special hearing in Los Angeles, which Sonnen and his lawyers requested after being notified of the suspension, will also address the fighter's legal troubles in his home state of Oregon. Sonnen pled guilty in January to money-laundering charges related to his real-estate business and was sentenced to 24 months probation, a $10,000 fine, and loss of his real-estate license. Coupled with questions regarding the veracity of Sonnen's testimony, Dodd is concerned the 34-year-old fighter is bringing "discredit to the mixed martial arts community," which is grounds for indefinitely suspending his license.

Sonnen confirmed in an email to ESPN.com on Tuesday that he would attend the hearing. He and his representatives have until Thursday to provide the panel with documentation related to their presentation, as well as a list of potential witnesses.

Josh Gross covers mixed martial arts for ESPN.com.