A University of Newcastle researcher has questioned whether the senior doctors who help companies sell drugs are independent experts, or simply drug representatives in disguise.
A report by Ray Moynihan in the latest edition of the British Medical Journal examines the role of the influential experts paid by industry to "educate" the profession and the public.
Mr Moynihan said pharmaceutical companies regularly sponsored leading specialists with generous fees to peddle influence and promote drugs to the profession and the public.
"Drug companies will pay influential doctors up to $400 an hour to act as key opinion leaders, and some doctors earn more than $25,000 a year in advisory fees."
Mr Moynihan's report features comment from industry insiders that key opinion leaders are used like salespeople to boost prescriptions of products.