The estranged father of a research scientist who outed herself as former call girl and blogger Belle de Jour revealed today he had used more than 150 prostitutes himself and had even introduced his daughter to some of them.
Dr Brooke Magnanti, 34, who is currently working for The Bristol Initiative for Research of Child Health, decided to reveal her secret in a Sunday newspaper because she feared an ex-boyfriend might disclose Belle's true identity.
Speculation about who the author might be increased when her memoirs were turned into the television series Secret Diary of a Call Girl, starring Billie Piper.
She is currently part of a team researching the potential effects on babies of their mothers' exposure to toxic chemicals and said her colleagues, all female, had been "amazingly kind and supportive" when she revealed her past.
In an interview with the Daily Mail, Paul Magnanti, who lives in the United States, said that allowing his daughter to meet some of the sex workers when she was in her 20s had shown her the "human" face of prostitution.
Mr Magnanti, who has no contact with his daughter and is divorced from her mother, said: "I have been with over 150 prostitutes.
"Of those, four or five were deep emotional relationships, and Brooke met those women. She saw that prostitutes were human. They were women.
"Brooke did not approve of me seeing the prostitutes, not because they were selling their bodies for sex but because of their drug use.
"We had a very big falling out. Brooke said some harsh things that she hoped would help me - but which had the opposite effect."
The former plumber said he was proud of his daughter but was relieved that she had given up sex work.
He told the newspaper: "She has not done anything wrong. Brooke is a very independent woman, and I support whatever she has done."
He added: "I am glad that she is no longer a prostitute. In my experience prostitution is wrong and corrupts people. I know that from my own experience.
"It only leads to heartbreak, but I will not condemn her for doing what she had to do to pay for her education."
Dr Magnanti said her mother had been "fully supportive" when she broke the news of her secret identity to her at the weekend.
In a statement yesterday she said: "My mother is being fully supportive and says she's 'not one to judge'.
"I, for one, am happy and relieved."
A spokesman for her employer, the University of Bristol, said: "This aspect of Dr Magnanti's past is not relevant to her current role at the university.
"Anything else might be of interest to people but it's not relevant to what she's doing."
Dr Magnanti, who studied anthropology and maths in Florida, was completing a PhD at Sheffield University's department of forensic pathology when she became a call girl.
She moved to London to find work while completing her thesis and preparing for her viva voce, the oral examination on her research, but spent her savings quicker than expected.
Working as a call girl allowed her to make money and have enough spare time to complete her work.
Realising she had no objection to having sex for money, she contacted an agency and worked as a prostitute from 2003 to late 2004 which she said was "so much more enjoyable" than her shifts in another job as a computer programmer.
She kept her double life a secret even when she started the blog describing her experiences and the books which followed.
Dr Magnanti said her decision to go public was also prompted by comments last month by Dr John Sentamu, the Archbishop of York.
He said the "fiction" of stories like Belle de Jour's created a "myth" that sex workers were independent women, empowered by the hold they had over men, who treated it like any other job.
Dr Magnanti said she was annoyed by the accusation that her stories were fiction: "You can't say I'm not real, and that my experience isn't real, because here I am."
She admitted some sex workers have "terrible experiences" but said she was "unbelievably fortunate".
An entry on the Belle de Jour blog website on Sunday said: "It feels so much better on this side. Not to have to tell lies, hide things from the people I care about. To be able to defend what my experience of sex work is like to all the sceptics and doubters.
"Anonymity had a purpose then - it will always have a reason to exist, for writers whose work is too damaging or too controversial to put their names on.
"But for me, it became important to acknowledge that aspect of my life and my personality to the world at large."
A statement on the website for Orion Books, which published Belle de Jour's novels, said: "It's a courageous decision for Belle de Jour to come forward with her true identity and we support her decision to do so.
"We have published her since 2005 and we are looking forward to continuing that relationship."