The Royal Commission into Institutional Responses to Child Sexual Abuse will this week host the next bout of a 12-year battle over whether the Catholic Church can be sued for damages under common law, with lawyer and victim John Ellis once again facing off against Cardinal George Pell.

In 2002, Cardinal Pell, as Archbishop of Sydney, wrote to Mr Ellis telling him the aged priest who had abused him for years was too old to deal with his complaint.

Facing off: Lawyer and victim John Ellis. Credit:Darren Pateman

The Ellis case, which went to the High Court in 2007, has been a curse for victims seeking to sue the Catholic Church because it established in case law, in effect, that the trustees that hold the assets of a church diocese cannot be sued because they are not responsible for the diocese's activities.

In other words, the church lacks a corporate identity to sue.