Survivors and descendants of those killed in Indonesia’s anti-communist purge of 1965-1966 are urging Western countries to apologise for their roles in what the CIA has itself described as “one of the worst mass murders of the 20th century”.

The spotlight on the West’s role in the state-backed genocide, which claimed the lives of at least hundreds of thousands of Indonesians, has intensified with the recent declassification of British documents revealing that a shadowy propaganda unit of the UK’s Foreign Office helped to incite the massacres.