US documents showed that the operation was not purely defensive, as later claimed; at a joint 1958 conference in Canada the US chemical corps minuted "it was agreed ... studies should be continued on aerosols ... all three countries should concentrate on the search for incapacitating and new-type lethal agents".
[3] The experiments were carried out at sea, off the coast of the Isle of Lewis in the Outer Hebrides, aboard a floating pontoon, supported by the ship Ben Lomond.
The incident was dealt with at the highest levels of government, going through the First Sea Lord to the Chancellor of the Exchequer Rab Butler, who was deputising for the absent Winston Churchill.
[2] Civil servant Clive Ponting, who had been acquitted by a jury in a "perverse verdict" after leaking secret documents about the sinking of the ARA General Belgrano in the Falklands War, in 1985 came across the one file that had not been destroyed, and confidentially told The Observer newspaper about it,[5] leading to a story that July headlined British germ bomb sprayed trawler.
[3] In 1994, the local Member of Parliament, Calum Macdonald called upon[6][7][8] the then-Secretary of State for Defence, Malcolm Rifkind, to commission an independent report on Operations Cauldron and Hesperus in 1952 and 1953, and all similar chemical weapons tests about which the public reasonably seek reassurance.
In his letter, Dr Pearson said: The papers on Operations Cauldron and Hesperus are classified, and it would not be in the national interest to make these available as the information therein could be misused by states seeking to acquire a biological weapons capability.
Dr Pearson added: The safety aspects of handling, transport and packaging were all carefully addressed to ensure there was no danger to any of those engaged in the trial.
He continued to outline his belief that it was not satisfactory that the same Government organisation which carried out potentially highly dangerous experiments should be allowed to pass the final judgment on itself regarding the health implications both then and subsequently.