The Roman Catholic diocese of Antigonish, N.S., is facing a class-action lawsuit from people who say they were sexually abused by priests who operated under the protection of the church  over several decades.

The lawsuit was initiated by Ron Martin, a New Waterford man who claims he was abused as a boy by priest Hugh Vincent MacDonald.

His brother, David Martin, made the same claim in a suicide note in 2002.

MacDonald was charged with rape, buggery and indecent assault involving more than 15 children. He died in June 2004 before the case went to court.

The lawsuit claims that the Roman Catholic Church, under instructions from the Pope, had a policy to keep sex-abuse allegations against priests secret, with ex-communication as the penalty.

"The lawsuit alleges that there was a conspiracy of silence within the Roman Catholic Church and that the church's policy of secrecy resulted in sexually abusive priests in the Antigonish diocese being able to molest children in the diocese without fear of public exposure," lawyer John McKiggan said in a release.

The suit claims the church, diocese and bishop sent priests from the Antigonish diocese for treatment for "sexual deviations," but kept it secret and didn't protect children.

Bishop Raymond Lahey, the Roman Catholic diocese of Antigonish and the Roman Catholic Church are all named in the suit.

McKiggan said he expects more victims of sexual abuse by priests to come forward.

In an open letter, Martin says he wants the church to acknowledge what happened to him.

"The only thing that I had asked for was an acceptance of responsibility for what happened to David, to us, and all the others who had been abused by a representative of the church," he said.

Three priests in the diocese, Clair Richard, Claude Richard and James Mombourquette, have been convicted of sexually abusing children in the diocese.