The L.A. County Sheriff's Department is currently investigating The Biggest Loser over reports of illegal and prescription drug use on the set of NBC's long-running reality show, according to Deadline.The news comes on the heels of reports last week that former contestant Suzanne Mendonca was preparing to file a class action lawsuit against the show, alleging abuse on the part of the producers during filming. Mendonca said contestants were encouraged to take drugs, among other alleged indiscretions.In a statement to Deadline, the department said that authorities from the Malibu/Lost Hills Station are "conducting an inquiry regarding the unsubstantiated allegations" from former contestants.Investigators may hit a roadblock because the King Gillette Ranch in Calabasas where the show was filming was torn down last fall after The Biggest Loser: Temptation Island finished production.Former Biggest Loser contestants plan to sue the show for alleged abuseNBC has yet to speak publicly on the matter, but show producer EndemolShine North America said in a statement: "The safety and well-being of our contestants is, and has always been, paramount. ... Contestants are told at the start of the show that there is zero tolerance for any weight-loss drugs. We prohibit the use of any illegal substances, in addition to the many other rules and procedures of the show that are designed to ensure safety."The Biggest Loser has yet to be renewed for an 18th season.