One of the best kept literary secrets of the decade was revealed last night when 34-year-old scientist Dr Brooke Magnanti announced she was the writer masquerading as call girl Belle de Jour.

The author behind the bestselling books detailing her secret life as a prostitute decided to come out to one of her fiercest critics, Sunday Times columnist India Knight, after claiming anonymity had become "no fun". "I couldn't even go to my own book launch party", she said.

Until last week, even her agent was unaware of her name. But now Magnanti, a respected specialist in developmental neurotoxicology and cancer epidemiology in a hospital research group in Bristol, has spoken of the time six years ago she worked as a £300 an hour prostitute working through a London escort agency. Magnanti turned to the agency in the final stages of her PhD thesis when she ran out of money. She was already an experienced science blogger and began writing about her experiences in a web diary later adapted into books and a television drama starring Billie Piper.

Magnanti saysshe has no regrets about the 14 months she spent as a prostitute. "I've felt worse about my writing than I ever have about sex for money," she said.

A month ago she revealed her secret to her colleagues at the Bristol Initiative for Research of Child Health, who were "amazingly kind and supportive". She was preparing to tell her parents this weekend.

Magnanti said she was working on a doctoral study for the department of forensic pathology of Sheffield University in 2003 when she began her secret life. "I was getting ready to submit my thesis. I saved up a bit of money. I thought, I'll just move to London, because that's where the jobs are, and I'll see what happens.

"I couldn't find a professional job in my chosen field because I didn't have my PhD yet. I didn't have a lot of spare time on my hands because I was still making corrections and preparing for the viva and I got through my savings a lot faster than I thought I would."

Unable to pay her rent, Magnanti's mind turned to other things. She told the Sunday Times she wanted to start doing something straightaway, "that doesn't require a great deal of training or investment to get started, that's cash in hand and that leaves me spare time to do my work in" Her solution was prostitution.

"I did have another job at one point, as a computer programmer, but I kept up with my other work because it was so much more enjoyable."

Magnanti said her future lies in medical science, but she also has a literary streak. She has been writing a novel, and the Belle blog will "continue for a bit — I'd like her to have happy ending".