Secret Diary of a Call Girl is a British television drama broadcast on ITV2 based on the blog and books by the pseudonymous "Belle de Jour," starring Billie Piper as "Belle", a high-class London call girl.
The series was written by Lucy Prebble, who is also known as the author of The Sugar Syndrome and ENRON.
The fourth and final series began on 1 February 2011, on ITV2.
Billie and the Real Belle Bare All is a one-off television program that aired on ITV2 on 25 January 2010, ahead of the Series 3 premiere of Secret Diary of a Call Girl.
The program, which took place at The May Fair, consisted of Billie Piper, who stars as Hannah Baxter in Secret Diary of a Call Girl, interviewing Dr. Brooke Magnanti, a former call girl who, until November 2009 remained anonymous known only by the pseudonym "Belle de Jour".