Philadelphia (CNN) -- The troubled Archdiocese of Philadelphia said Monday that it has ousted two priests due to allegations of sexual abuse of minors.
The allegation against Monsignor George Mazzotta, 73, first came to light in May 2010 and was reported to law enforcement. The archdiocese called it a "substantiated allegation," but provided no details.
Since that time, Mazzotta "has not been permitted to exercise his public ministry, wear clerical garb or present himself publicly as a priest," the archdiocese said in a statement.
Monsignor Hugh Campbell, 77, reported himself for sex abuse in December and was placed on administrative leave. Law enforcement authorities were also notified of the reported abuse.
Both men have been found "not suitable for ministry," the archdiocese said.
The archdiocese has been under fire since 2011 for what experts have called one of the most sweeping sex scandals in America. At least 26 priests have been put on administrative leave in connection with the scandal.
The action against Mazzotta and Campbell, who retired in 2007, is not connected to those cases.
A grand jury last year charged four Philadelphia priests and a parochial school teacher with raping and assaulting boys in their care. Two church officials are currently on trial in the case -- the Rev. James Brennan, who is accused of the attempted rape of a 14-year-old, and Monsignor William Lynn, who is accused of covering it up. They have pleaded not guilty.
Defrocked priest Edward Avery was due to also go on trial with Brennan and Lynn, but pleaded guilty in March to involuntary sexual deviate sexual intercourse after admitting to sexually assaulting a 10-year-old altar boy during the 1998-1999 school year at St. Jerome Parish.
Charles Engelhardt and Bernard Shero, a teacher at the school, are charged with assaulting the same boy in 2000. They have pleaded not guilty and are due to go on trial in September.
The trial represents the first time that U.S. prosecutors have charged not just the priests who allegedly committed the abuses, but an official who stands accused of failing to stop the assaults. Lynn had been responsible from 1992 until 2004 for investigating reports that priests had sexually abused children.
The grand jury alleged that Lynn knowingly allowed dangerous priests to continue in the ministry in roles in which they had access to children.
CNN's Sarah Hoye contributed to this report.