PROVIDENCE, R.I.—A group that advocates for victims of clergy abuse wants authorities to investigate the Legion of Christ, a disgraced Roman Catholic order.

Two lawsuits in Rhode Island claim the Legion of Christ deceived elderly donors into giving it millions at the same time its officials knew the church was investigating its founder, the late Rev. Marcial Maciel, for allegations including sex abuse. The order has said its actions in both cases were proper. A spokesman for the Legion did not return messages seeking comment this week.

The Vatican took over the order in 2010 after the investigation determined that Maciel had fathered three children and molested seminarians. In December, the Legion admitted a superior in charge of American priests-in-training sexually abused a minor at the Legion's novitiate in Cheshire, Conn., where he was novice director from 1982 to 1994.

David Clohessy, executive director of the Survivors Network of those Abused by Priests, said on Thursday that Rhode Island and Connecticut law enforcement should investigate.

"The Legion's known and suspected wrongdoing is so persistent and widely documented that we think action by law enforcement is warranted. No institution can or should be allowed to essentially police itself," he said.

Mark A. Dupuis, a spokesman for the Connecticut Division of Criminal Justice, said they have no complaints pending against the Legion, but if anyone wishes to make a complaint it would be reviewed and acted on as appropriate.

Rhode Island State Police did not return a message seeking comment.

One of the Rhode Island lawsuits claims a late Yale University professor was coerced, defrauded and deceived into signing over between $1 million to $2 million in assets to the Legion before he died in 2009. The man's son, Paul Chu, says his father was led to believe Maciel was a saint, even as Legion officials knew about serious allegations against him.

The other lawsuit was brought in state court by the niece of Gabrielle Mee, a woman who gave some $60 million to the order. A Superior Court judge said there was evidence Mee had been unduly persuaded to give the Legion her money, but also said the niece did not have standing to sue. The decision is being appealed.

The lawyer in the Mee case, Bernard Jackvony, said the office of Rhode Island Attorney General Peter Kilmartin had access to files in the case, and he said he hoped they would get involved in it as a civil or criminal matter. To his disappointment, it has not.

Kilmartin's spokeswoman, Amy Kempe, said there are many hurdles that must be overcome for the office to get involved in a private, civil dispute over a will, and that courts elsewhere have criticized attorneys general when they have gotten involved in similar cases. She said the office had urged Jackvony to take any allegations of criminal wrongdoing to state police.