Catholic group Opus Dei wants "references that hurt Catholics" to be removed from the film version of Dan Brown's hit novel The Da Vinci Code.
The Da Vinci Code has sold more than 30 million copies
"The Da Vinci Code offers a deformed image of the Catholic Church," Opus Dei said in a statement released in Rome.
But the group added it would not call for a boycott of the highly anticipated film, due out in May.
The book portrays Opus Dei as a power-hungry movement bent on covering up the truth about Christ's bloodline.
The group did not say in its statement which references it wanted removed, but studio Sony insisted the movie was a work of fiction.
The film was "not a religious tract, and it is certainly not meant to criticise any group, religious or otherwise," said Jim Kennedy of Sony Pictures Entertainment.
Opus Dei said changes to the film would be appreciated by Catholics "particularly in these days in which everyone has noted the painful consequences of intolerance" - a reference to the violent protests sparked by the publication of cartoons satirising the Prophet Muhammad.
However, it said it would not urge boycotts, and would follow a "more constructive" path.
The novel, full of conspiracy theories in a thriller style, is about two code-breakers who try to track down the truth behind the Holy Grail. It has caught the imaginations of millions.
Tom Hanks stars in the film of the best-selling book
The Roman Catholic Church has said the book is pure fiction.
The film, starring Tom Hanks and Audrey Tautou, will premiere at the Cannes Film Festival in May.
Opus Dei was formed in 1928 in Madrid by the priest Josemaria Escriva de Balaguer. Its name means "the work of God".
The fundamental idea was to encourage Catholic lay people to see religion as something that should direct every minute of their lives, rather than being a matter of just turning up for Mass and confession.
Members are expected to live holy lives, evangelise people they know, and observe daily religious devotions.