Writing on the Microsoft blog, Mr Frank referred to allegations that 'Microsoft employees and business partners may have engaged in illegal activity in Pakistan and Russia'. He went on: '…we take every allegation seriously, and we cooperate fully in any government inquiries. Like other large companies with operations around the world, we sometimes receive allegations about potential misconduct by employees or business partners, and we investigate them fully, regardless of the source.'

Microsoft has a team of over 50 people whose job it is to investigate potential breaches of company policy. There are another 120 in the compliance department.