Pope Francis has announced a reorganisation of the oversight and administration of the Vatican's financial affairs, a move that appears to have reduced the power of his financial czar, Cardinal George Pell.

In a new law announced on Saturday, Pope Francis essentially reversed a 2014 law that had transferred the main operational section of the patrimony office to the cardinal's Secretariat for the Economy.

Francis says he was restoring these administrative functions to the APSA office because he realised there needed to be an "unequivocable and full separation" between those who manage Vatican assets (APSA) and those who supervise them (Cardinal Pell).