Four arrests made in UK over 'Petya' cyber attack

Latest: Four arrests have been made as part of an investigation into computer software service fraud, thought to cost hundreds of millions of pounds worldwide.

Update 10:46am: Four arrests have been made as part of an investigation into computer software service fraud, thought to cost hundreds of millions of pounds worldwide.

Through a collaboration between the City of London Police and Microsoft, the investigation has been looking into the tens of thousands of reports of software service fraud made each year.