Britain's role in supplying information to an American military "kill list" inAfghanistan is being subjected to legal challenge amid growing international concern over targeted strikes against suspected insurgents and drug traffickers.

An Afghan man who lost five relatives in a missile strike started proceedings against the Serious Organised Crime Agency (Soca) and the Ministry of Defence demanding to know details of the UK's participation "in the compilation, review and execution of the list and what form it takes".