[5] The story has been met with scepticism, given the absence of any indication that Heydrich displayed any of the highly distinctive symptoms of botulism.

[6] In 1940 Fildes was put in charge of a newly created department, the Biology Department, Porton (BDP) at Porton Down to study the defensive implications of a bacterial attack and there built up a team of microbiologists to study the use of biological weapons, including anthrax and botulinum toxin.

An early project was the creation of a stockpile of a million anthrax impregnated cattle cakes to be used in a possible retaliatory attack.

In 1942 it famously carried out tests of an anthrax bio-weapon developed at Porton Down at Gruinard Island.

[9] After the war Fildes worked at the Sir William Dunn School of Pathology in Oxford, headed by Nobel Prize winner Sir Howard Florey, to study on the biochemistry of bacteriophage T1 (and to a lesser extent, T2) multiplication.