 In 2006, allegations that Falun Gong practitioners had been killed to supply China's organ transplant industry prompted an investigation by former Canadian Secretary of State David Kilgour and human rights lawyer David Matas.In July 2006, the Kilgour-Matas report questioned "the source of 41,500 transplants for the six year period 2000 to 2005" and thereby inferred that "the government of China and its agencies in numerous parts of the country, in particular hospitals but also detention centres and 'people's courts', since 1999 have put to death a large but unknown number of Falun Gong prisoners of conscience".The authors of the Kilgour-Matas report reached their conclusion via circumstantial evidence and inference from this evidence.