Senior British diplomats introduced an extraordinary “licence to kill” law in an attempt to legalise retrospectively the colonial-era killing of 24 villagers by UK troops in Malaysia, the Observer can reveal.

The Batang Kali massacre took place on 12 December 1948, as British troops carried out a counter-insurgency operation against Chinese Malayan communists. The shootings took place after a 16-man patrol group of Scots Guards surrounded a rubber estate at Sunga Rimoh by the Batang Kali river. The bodies of several unarmed villagers were reportedly mutilated and the village was burned to the ground.