Relations with France became strained when French agents of the DGSE bombed and sank the Greenpeace ship the "Rainbow Warrior" on 10 July 1985 while it lay moored in Auckland Harbour, killing photographer Fernando Pereira. In June 1986 Lange obtained a political deal with France over the "Rainbow Warrior" affair, presided over by United Nations Secretary-General Javier Pérez de Cuéllar. France agreed to pay compensation of NZ$13 million (US$6.5 million) to New Zealand and also to apologise. In return, Lange agreed that French authorities could detain the convicted French agents Alain Mafart and Dominique Prieur at the French military base on Hao Atoll for three years. However, both spies were freed by May 1988, less than two years later, in violation of the agreement.