By Ben Davies
BBC News reporter
A woman who led protests against the Da Vinci Code dressed in a habit is not a real nun, says the Catholic Church.
The 'nun' is said to do good work with people on the fringes
Sister Mary Michael appeared in the world's media denouncing the controversial book as "blasphemy".
The Catholic Church says Sister Mary is not "canonically recognised" even if she does do "good works".
She was connected to the Carmelites but left and is now a "maverick" and a "one-woman order", a spokesman told the BBC News website.
Sister Mary Michael hit the headlines in August 2005 after she mounted a prayer vigil outside Lincoln Cathedral while the Da Vinci Code was filmed there.
Though she had not read the book by Dan Brown at the time, she was pictured kneeling outside the Anglican Minster which was paid £100,000 to allow filming to take place.
The story revolves around the theory that Jesus married Mary Magdalene and their descendants survive today.
The blockbuster has caused outrage among many Christian organisations, including senior officials at the Vatican.
Having read the book and then "thrown it in the bin", Sister Mary Michael took her protest to Cannes earlier this month where the film was first shown.
Asked about her status as a nun, Sister Mary Michael said: "I am attached to the Carmelites and that's it."
But the spokesman for the Nottingham diocese in which she lives, Rev Philip McBrien, said: "Her connection with the Carmelites ended a long time ago. She has never been professed by our bishops and she doesn't belong to any recognised order.
"She has no official connection with any order or any of the parishes. She's a one-off, a maverick.
"She dresses more nun-like than any nuns I know."
When these comments were put to Sister Mary Michael she acknowledged her life was "unusual" but insisted she is "still officially a nun".
"The bishop knows all about me, he knows why I wear my habit and so on. It is unusual, I can say no more. I can't even understand it myself but I've never done anything underhand - I can't with this personality.
"I am Our Lady's sister of peace and mercy and I am attached to the Carmelites and you can just put it there and that's what I am."
After three and a half years in a closed Carmelite order Sister Mary Michael left, but decided to continue wearing a habit similar to what she had worn when a nun - albeit modified according to her own design.
Nottingham diocese's Monsignor Thomas McGovern said: "It's very much a personal vocation as far as she's concerned. I would say even if not officially recognised she is doing a lot of good work."
Sister Mary Michael, 61, says all she has been doing with her Da Vinci Code protests is standing up for the truth.
"I am standing up for what every Catholic should believe in the true body, blood, soul and divinity of our lord."