The Church of England disregarded dozens of allegations in its inquiry into child sexual abuse and then downplayed the issue to protect its reputation, a critical report has found.

A report by former Barnardo's chief executive Sir Roger Singleton found that close to 100 cases were whittled down to just a handful for a review released in 2010.

Inconsistent and overly specific criteria reduced the number of cases they reported for the Past Cases Review, leading it to conclude after examining 40,000 files that just 13 cases of alleged child sexual abuse merited formal action.

Sir Roger, who was commissioned to complete an inquiry into the review, said he believed the Church "downplayed" the issue in public statements to avoid reputational damage.

However, he also said he found "no evidence whatsoever of a deliberate attempt to mislead" or that anyone broke the law.

"In the public statement that it issued reporting on the review, [the Church] rather failed to give a comprehensive picture of the concerns that existed," he said.

"It narrowed down the definitions of who had actually been responsible for abuse by limiting it to just new cases and cases where the Church took formal action. This had the impact of reducing the numbers from probably nearer 100 to just two which appeared in the public statements."