Adrian Cohen, a Sydney-based doctor who has traveled the world as medical director for CBS' Survivor reality series, admitted on Monday to misconduct that included cocaine use and inappropriately obtaining prescription drugs, according to The Daily Telegraph, an Australian newspaper.

In a hearing before the New South Wales Medical Tribunal on Monday, Australian medical authorities claimed Cohen "regularly used cocaine" to "self-medicate" from 1998 to 2003.  Cohen alleged obtained the pharmaceutical grade cocaine powder by using some of his patients' name to write improper prescriptions.  He was also accused of inappropriately obtaining free "Doctor's Bag order" drugs, which are designed to provide doctors with free medication in emergencies, and using them for his commercial business, The Daily Telegraph reported. 

Cohen admitted to using the free "Doctor's Bag order" drugs for his private contracts, including at the Sydney Cricket Ground Trust, where he was paid to provide emergency treatment at sporting events.  "I have admitted it was inappropriate," said Cohen.  "We made money from it (but) I certainly didn't make myself rich by doing it." 

In addition to working as medical director on numerous seasons of Survivor and Eco-Challenge, both of which were created by Mark Burnett, Cohen has made regular appearances on Oprah and has also worked on the sets of Baywatch and Mission Impossible 2

Another accusation facing Cohen is that he "procured a large supply of wholesale drugs" -- which included prescription painkillers and asthma medication  -- despite not having the appropriate wholesale license.  He then allegedly used the drugs on the sets of Survivor and Eco-Challenge.

In his defense, Cohen said the large amount of medication was necessary because of the shows' "isolated sets," where the nearest hospitals were often several hours away and only accessible via helicopter.  In evidence presented at the tribunal hearing, Cohen said while working on Survivor: The Amazon, he was required to help a local, not a contestant, who was "badly injured" in a machete fight.

"We were five hours from the nearest town and there was a Saturday night machete fight and we got the loser," Cohen said.

As far as his own cocaine habits, Cohen told the tribunal his first recreational use of the drug was "at a party" in the U.S. in 1998 while he was in the country for a series of business meetings.  From there he described his cocaine use as "sporadic and unpredictable" and added it was brought about by the stresses caused by his "unique business."

The New York Post reported on Wednesday that it is unknown if Cohen will continue to work for Burnett on SurvivorThe Daily Telegraph added Cohen's hearing is expected to continue.