Last month David Cameron revealed to parliament during an emergency debate on the refugee crisis that he had authorised the targeted killing by drone of a UK citizen, Reyaad Khan, who had signed up as an ISIS fighter.

Cameron's revelation of the strike dominated the following day's headlines, which had previously been focused on the refugee crisis in the wake of the huge public response to photographs last month of the body of 3-year-old Aylan Kurdi washed up on a beach.

The prime minister revealed in his Commons statement that he had sought the attorney general's legal opinion before authorising the strike, which was carried out on 21 August and also killed another UK citizen, Ruhal Amin. Cameron said the strike was justified as both were a direct risk to UK national security.

However, the announcement – the first of its sort from the UK – also raised significant questions as to the legal basis for the strike, as well as the decision-making behind the timing of the public statement.

A human rights group has already said it intends to challenge Cameron's decision through judicial review, while commentators and academics alike have suggested the timing of the announcement served to divert attention away from debate of Europe's refugee crisis.

BuzzFeed News sent the following request to the attorney general's office, using UK freedom of information laws: