Andrew Wakefield is back in the news after being accused of concealing a potential conflict of interest in his 1998 study purporting to link the measles, mumps and rubella vaccine to autism and bowel cancer.
Richard Horton, editor of The Lancet , this week said he would not have published the paper had he known that Dr Wakefield was being paid for a study looking for evidence to support legal action by parents who thought their children had been damaged by the vaccine.
The General Medical Council is considering whether to take action against Dr Wakefield. Dr Wakefield has insisted on an inquiry.
The original controversy surrounding the study has already cost Dr Wakefield his post at the Royal Free Medical School - he resigned in 2001.
Speaking at the time, he said: "I have been asked to go because my research results are unpopular."
The 46-year-old medic was born into the profession - his mother was a GP and his father a neurologist. He studied medicine at St Mary's Hospital Medical School in London then trained in bowel transplantation at Toronto University, Canada, where he worked as a transplant surgeon.
In the late 1980s, he returned to the UK and published studies that, he suggested, showed a link between measles and Crohn's disease, a form of inflammatory bowel disease. By the mid-1990s, Dr Wakefield started to consider whether there was a link between the MMR vaccine and autism and bowel disease.
His study focused on tests carried out on 12 children referred to the Royal Free Hospital in Hampstead for gastrointestinal problems. At the same time, Dr Wakefield was paid to carry out another study to find out if parents who claimed their children were damaged by the MMR vaccine had a case. He insists that the two studies were completely separate.