PORTLAND — Six men have sued the Roman Catholic Diocese of Portland, claiming church leaders concealed allegations that a priest sexually abused children for decades.

The suits, filed in November by men from Maine, New Hampshire and New York, were made public this week and accuse the diocese of covering up abuse by the Rev. James Vallely. The men say Vallely sexually abused them from 1958 to 1977 when they were ages 8 to 15.

Their lawyer, Mitchell Garabedian, said Tuesday that the suits claim the church “fraudulently concealed” Vallely’s abuse. Vallely died in 1997 in Florida.

The concealment claim opens the way to sue even though the statute of limitations for sexual abuse has expired. Garabedian said former Bishop Daniel Feeney, who led the diocese from 1955 until his death in 1969, knew Vallely abused minors but did nothing, allowing him to continue to abuse children.

The evidence that Feeney was aware of the abuse came from a letter revealed recently as part of a separate lawsuit that indicated the diocese knew about Vallely’s abuse in 1956, Garabedian said. The diocese had previously said it knew of credible allegations against Vallely going back only to 1977. Written in July 2005, the letter from one priest to another in the diocese says Feeney transferred Vallely to a different parish in 1956, shortly after learning of the sexual abuse allegations.

“I have no evidence indicating that Bishop Feeney warned the public to protect their children against Father Vallely,” said Garabedian, who brought the lawsuit against the Rev. John Geoghan that sparked the church abuse scandal in Boston more than a decade ago. “Father Vallelly was shuttled from parish to parish to parish, as were so many other abusers.”

Diocesan spokesman David Guthro said the diocese couldn’t comment on a pending lawsuit. The diocese’s lawyer, Gerald Petruccelli, said he got the complaints Tuesday morning and couldn’t immediately comment on the claims.

The suit is seeking unspecified monetary damages.

“What my clients are seeking is validation and a monetary award will be validation,” Garabedian said. “They want to regain self-esteem and self-respect.”