It was sensational stuff that riveted a nation: A mild-mannered American doctor poisons then dismembers his unfaithful wife, flees England in disguise with his mistress -- and is caught, tried and hanged.

The problem is that the poisoned corpse that sent Dr Hawley Crippen to the gallows in London in 1910 was not that of his wife, according to new evidence found by U.S. researchers.

A team led by John Trestrail, head of the regional poison centre in Grand Rapids, Michigan, took mitochondrial DNA -- genetic material passed on through the mother -- from a tissue sample from the corpse kept in a London museum.