The Islamic State (IS) militants have released a video purportedly showing the execution of British aid worker David Haines.
The UK Prime Minister David Cameron on Saturday said the murder of David Haines is an "act of pure evil" in a tweet, after the release of a video purporting to show the UK hostage's beheading, the CNN reported.
Haines, an aid worker from Perth was taken hostage in the village of Atmeh, in Syria, in March 2013. The 44-year-old had been helping French agency ACTED deliver humanitarian aid.
His execution comes hours after his family had made a direct appeal to IS to contact them on Friday.
IS also known as ISIS (Islamic State of Iraq and Syria) released a video on September 2 showing the beheading of American journalist Steven Sotloff, who was kidnapped in Syria in August 2013. Another American journalist, James Foley, was executed and a video was released August 19.
