Walter Seddon Clayton (24 March 1906 – 22 October 1997) was a key organiser of the Communist Party of Australia (CPA) in the 1930s and 1940s and suspected of being the Australian-based Soviet spymaster code-named KLOD, although the Australian Security Intelligence Organisation (ASIO) and MI5 were not able to provide any conclusive evidence of this for fear of tipping off the Soviets that their cable traffic was being deciphered and read by Western intelligence agencies.
Clayton migrated from New Zealand to Australia in 1930 and joined the Communist Party of Australia in 1933. He quickly moved up the ranks within the CPA, becoming responsible for the organisation and operation of the undercover and clandestine apparatus for the CPA while the party was outlawed. Clayton spent most of the 1940s and 1950s underground, playing a game of cat and mouse with the police and officers of the Australia's newly formed security service (ASIO).
Clayton was born in New Zealand before settling in Melbourne, Australia in 1931, where he sold bags and goods wholesale.
Incensed by the Great Depression of the 1930s, Clayton joined the Communist Party of Australia (CPA) in 1933 where he quickly moved up the ranks. Clayton was well known for his public "soap box" appearances and was arrested in 1938 for protesting against a visit to Australia by a Nazi yachtsman.
Clayton was also "nabbed" during a police raid shortly after the CPA was declared illegal (in June 1940). Clayton was kept under investigation for his connections with the CPA. However, he went underground and was rarely seen again until his appearance at the Petrov Royal Commission. Some time in the 1940s, Clayton became a member of the CPA's Central Control Commission, which was responsible for internal discipline and the clandestine operations of the party.
While never charged with espionage or treason, Clayton was believed to be the Soviet spymaster code-named KLOD, who coordinated a network of spies in Canberra during the 1940s and early 1950s. According to Venona decrypts, KLOD received classified (and some not-so-classified) documents and information from a network of about 10 spies and passed this information to his Soviet handlers.
One of the decrypted Venona reports indicates that Clayton was embarrassed when paid for information that he provided in 1945. Clayton explained to his Soviet handler that he passed information for 'duty'.
In May 1954, Clayton briefly emerged from hiding to appear at the Royal Commission on Espionage, which was the government's response to the Petrov affair. At the inquiry, Clayton denied ever having met anyone from the Soviet embassy and could not recall having met either Jim Hill or Ian Milner. Clayton mocked ASIO by going back into hiding shortly after his appearance at the Royal Commission.