A French drug maker has been found guilty of aggravated deceit and involuntary manslaughter over a weight loss pill at the centre of a major health scandal. The drug Mediator was developed for use in overweight diabetics and was on the market for 33 years. It was eventually withdrawn in 2009 over concerns it could cause serious heart problems. Hundreds of people are believed to have died as a result of the drug. Around five million people were prescribed the medicine over the course of three decades, despite various warnings over its side effects. Thousands of plaintiffs were involved in the trial, which began in 2019. Drug maker Servier had denied any knowledge of Mediator's side effects but a court on Monday issued it with a fine of €2.7m (£2.3m, $3.2m). "Although they knew about the risks for many years... they never took the necessary measures," judge Sylvie Daunis said. The company's former deputy chairman, Jean-Philippe Seta, was also given a four-year suspended prison sentence. France's medical regulator, meanwhile, was fined more than €300,000 for its role in the scandal. The judge found the body had "seriously failed" in its duties, according to the AFP news agency. Ahead of Monday's verdict, French pulmonologist Dr Irène Frachon, who is credited with exposing the drug's side effects, told AFP that she hoped the ruling would "give us the tools to understand how such deceit could have gone on for so long". A number of other European countries, including Italy and Spain, banned Mediator in the early 2000s. In France, however, it continued to be offered to diabetics and other patients as an appetite suppressant. One study concluded that 500 deaths could be linked to Mediator between 1976 and 2009. A second one put the figure at 2,000.