A paedophile priest recorded "hot" confessions with children, showed students a dead body and carried a gun at school, the Royal Commission into Institutional Responses to Child Sex Abuse has heard.

The royal commission has resumed in Melbourne and has turned its focus to historic child sex offences committed by clergy from the mid 1980s to 1996.

The hearing was told on Tuesday that the Catholic Church paid out more than $16.8 million in compensation to child abuse victims in Melbourne between January 1980 and February 2015.

In her opening address, counsel assisting the commission, Gail Furness, SC, said new data showed 454 people made a claim or substantiated complaint about child sex against priests, religious employees and volunteers during this period.

There were 316 claims that resulted in compensation – an average of $52,000 each. Most of the claims (335) were against priests, with most alleged abuse taking place at local parishes and schools.