When the two Indonesians, Osman Haji Mohamed Ali and Harun Said, were picked up in Malaysian waters three days after the MacDonald House bombing, they claimed to be fishermen whose boat had capsized.
But a marine police inspector suspected they were connected to the bombing and contacted the Criminal Investigation Department (CID).
The Indonesians told a CID senior inspector that they came from Java, looked for a target and set off two bundles of explosives at a building.
They were charged with the murder of the three victims.
During the 13-day trial, they claimed to be marine commandos and sought to be treated as prisoners of war under the Geneva Convention.But Justice Frederick Arthur Chua ruled that they were not entitled to this privilege as they had pretended to be civilians.
He called their act "cowardly" in sentencing them to death on Oct 20, 1965.
After two unsuccessful appeals, they were hanged on Oct 17, 1968.