Sten Forshufvud (1903-1985) was a Swedish dentist and physician, and amateur toxicologist (expert on poisons) who formulated and supported the controversial theory that Napoleon was assassinated by a member of his entourage while in exile. He wrote a book, in Swedish, about this in 1961. He later published his ideas in English, in a book on whose authorship Ben Weider collaborated.
Forshufvud tested five of Napoleon's hairs with Ben Weider for traces of arsenic. They found fluctuations of arsenic levels ranging from normal to 38 times greater than average. This would purportedly suggest that Napoleon was given arsenic in different concentrations at different times for almost five years prior to his death.
Forshufvud's findings have been disputed since the hairs that were tested have never been decisively dated, or even proven to be Napoleon's. However, all of the hair samples that Forshufvud had tested by an independent laboratory were family heirlooms that were handed down through generations. Plus all the samples were very similar. These hair samples were supposedly given to members of Napoleon's staff and others he favored. Several samples of these hairs did not pass through Forshufvud's hands and were sent directly to the testing laboratory in Scotland. All supported Forshufvud's theory.
Forshufvud and Weider suggest that their theory that Napoleon was assassinated by a Frenchman who served on Napoleon's staff during his exile (most likely suspect being Montholon) is repugnant to the French people who now honor Napoleon as one of France's great heroes. As a result, they understood that their "proof of poisoning" would always be questioned or ridiculed by those serving France. 
- Napoleonic Society: Dr Sten Forshufvud, A detective of history, accessed on June 15, 2009
- Forshufvud, Sten: Vem mördade Napoleon?: nya forskningsresultat som kastar ljus över dramat på S:t Helena, Bonnier, Stockholm 1961 (Swedish)
- Weider D, Forshufvud S. Assassination At St.Helena. 1983. Berkley Books.[page needed]
- Weider. Ben, and David Hapgood. 1982. The Murder of Napoleon. New York: Congdon & Lattes: Distributed by St. Martin’s Press.
- Weider, Ben, and Sten Forshufvud. 1983. Assassination At St. Helena: The Poisoning Of Napoleon Bonaparte. Berkley Books. ISBN 0-425-06050-0