Haigh was freed from prison in 1943 and became an accountant with an engineering firm. Soon after, by chance, he bumped into his former employer William McSwan in The Goat pub in Kensington. McSwan introduced Haigh to his parents, Donald and Amy. McSwan worked for them by collecting rents on their London properties, and Haigh became envious of his lifestyle. On 6 September 1944, McSwan disappeared. Haigh later admitted hitting him over the head after luring him into a basement at 79 Gloucester Road, London SW7. He then put McSwan's body into a 40-gallon drum and tipped concentrated sulphuric acid onto it. Two days later he returned to find that the body had become sludge, which he poured down a manhole.