Who leaked the MPs' expenses disk?

MPs' expenses: how scoop came to light – and why journalists fear a "knock on the door" | Media | The Guardian

That intermediary has been named by the Wall Street Journal, the Sunday Times and the Mail on Sunday as John Wick, a former major with the SAS who is a director of a private security company, International Security Solutions Limited [ISSL]. He is believed to have been assisted in his endeavours by Henry Gewanter, the American managing director of a PR firm, Positive Profile. Contacted by the Guardian yesterday, Gewanter declined to comment on whether he had been involved.

Finally, some reporting on the back story!