A Catholic layman who helped improve conditions for disabled people in multiple countries over half a century sexually abused at least six women, a report for his French-based charity has found.
The report released by L'Arche International on Saturday said the women's descriptions provide evidence to show Jean Vanier engaged in "manipulative sexual relationships" over a period from 1970 to 2005, usually with a "psychological hold" over the alleged victims.
Mr Vanier, a Canadian, died last year at the age of 90.
"The alleged victims felt deprived of their free will and so the sexual activity was coerced or took place under coercive conditions," the report said.
It did not rule out potential other victims.
None of the women were disabled, a significant point given the Vatican has long sought to portray any sexual relationship between religious leaders and other adults as consensual unless there was clear evidence of disability.
The #MeToo and #ChurchToo movements, however, have forced a recognition that power imbalances such as those in spiritual relationships can breed abuse.
During the inquiry, commissioned by L'Arche last year and carried out by the independent UK-based GCPS Consulting group, six non-disabled women said Mr Vanier had engaged in sexual relations with them as they were seeking spiritual direction.
According to the report, the women, who have no links to each other, reported similar incidents and Mr Vanier's sexual misconduct was often associated with alleged "spiritual and mystical justifications".
A statement released by L'Arche France on Saturday stressed some women still have "deep wounds".
The report noted similarities with the pattern of abuse of the Rev Thomas Philippe, a Catholic priest who Mr Vanier called his "spiritual father".
Rev Philippe, who died in 1993, has been accused of sexual abuse by several women.
In a letter to charity members, the leaders of L'Arche International, Stephan Posner and Stacy Cates Carney, told of their shock at the news and condemned Mr Vanier's actions.
"For many of us, Jean was one of the people we loved and respected the most," they wrote.
"While the considerable good he did throughout his life is not in question, we will nevertheless have to mourn a certain image we may have had of Jean and of the origins of L'Arche."
The allegations against Mr Vanier reveal a major gap in the Catholic Church's handling of sex abuse allegations to date.
Because he was a layman, he was exempt from the Vatican's in-house sanctioning procedures for abuse, which only cover priests, bishops and cardinals.
For these offenders, the worst penalty the Vatican can impose is defrocking - essentially making the priests laymen again.