Sir Richard Doll is a renowned epidemiologist who was secretly paid a large consultancy fee, at times reaching $1,500 a day, by chemical giant Monsanto for over 20 years, during which time he was investigated the cancer risks of the chemicals industry
According to a Guardian newspaper report, "While he was being paid by Monsanto, Sir Richard wrote to a royal Australian commission investigating the potential cancer-causing properties of Agent Orange, made by Monsanto and used by the US in the Vietnam war. Sir Richard said there was no evidence that the chemical caused cancer." 
"Documents seen by the Guardian reveal that Sir Richard was also paid a £15,000 fee by the Chemical Manufacturers Association and two other major companies, Dow Chemicals and ICI, for a review that largely cleared vinyl chloride, used in plastics, of any link with cancers apart from liver cancer - a conclusion with which the World Health Organisation disagrees. Sir Richard's review was used by the manufacturers' trade association to defend the chemical for more than a decade." 
- Sarah Boseley, Renowned cancer scientist was paid by chemical firm for 20 years, The Guardian, Friday December 8, 2006.