Retired Assistant Commissioner John Ure, who in 1995 was head of the North Region Major Crime Squad, said it was very disappointing to hear that the church was apparently aware of serious allegations concerning McAlinden at about the same time investigations were being undertaken into Ryan and Monsignor Patrick Cotter, who had "decided to say nothing" about Ryan's offending.

Mr Ure said in his view it would be a matter of serious concern if senior members of the church had known of allegations about McAlinden but failed to report them.

"Just imagine if a school principal discovered that a teacher was sexually abusing students and decided to transfer the teacher to another school or ask the teacher to resign, without referring the matter to police, and with the support of senior education officials," Mr Ure said.

"There would be justifiable outrage."

He said failing to report allegations of a serious crime to the police could in certain circumstances itself amount to an offence.

"Discussions about McAlinden were apparently occurring about the same time that Vince Ryan was charged with sexual abuse of children, and Monsignor Cotter was investigated about failing to report Ryan's abuse when it was brought to his attention.

"The allegations about McAlinden would have been investigated had we been told."

Police recommended charging the late Monsignor Cotter for failing to report allegations about Ryan to police, but the Office of the Director of Public Prosecutions declined to prosecute, mainly because of Monsignor Cotter's age.

In 2007 Mr Ure described the DPP decision as "justice denied".