He is also charged with possession of two category C indecent images of children and possessing a prohibited image of a child.

Shy, a US citizen, who lives in New Jersey, worked for the White House under president Barack Obama and secretary of state Hillary Clinton, was arrested in late February by Bedfordshire Police. He was charged the following day and appeared at Luton Crown Court via video-link from HMP Bedford on Friday wearing a grey prison-issue tracksuit.

He was not asked to enter a plea to any of the charges and was remanded in custody ahead of a hearing in June.