He was abducted in Buenos Aires Ezeiza airport by plain clothed agents of the Argentine security forces on 2 November 1974, as he was on his way to France.
[3] From there he was taken to Chile to the offices of DINA, the Chilean secret police, in José Domingo Cañas Street, Santiago, where his mother and sister Diana were being interrogated, and subsequently to the Villa Grimaldi torture centre.
[4] It is thought Beausire was a target for DINA because his sister Mary-Anne opposed the regime, and was living with Andrés Pascal Allende, a revolutionary and leading member of the MIR, then in the underground opposition to the military regime, and nephew of deposed Popular Unity Chilean president Salvador Allende.
The last anyone heard of William Beausire was on 2 July of that year, when witnesses reported seeing DINA officers taking him from a building in Irán Street, Santiago.
In 1981, his case was highlighted when featured in the BBC TV Prisoners of Conscience series, with Beausire being played by Richard Griffiths.