St John's Cathedral appears to be fighting a losing battle against plagiarising priests - a practise that has already led 17 families of believers to leave the Anglican church.
A former parishioner at the Emmanuel Church in Pok Fu Lam, a St John's affiliate, said four priests were guilty of using sermons from the internet and preaching them as if they were their own.
He said they had been doing so for 18 months.
The Very Reverend Matthias Der, the new dean of the cathedral, confirmed that some priests had persisted with their plagiarism despite his warnings against the practice at his first meeting with them in September.
"There is still bad practice in some of the priests," Der said on Friday, without confirming the number of clergy involved.
"I told my clergy that any kind of use of outside sources needs to be attributed," Der said of the September meeting.
"I understand that when we do research, we will look at other people's writing, but if we are using direct quotes then we need to attribute them. Plagiarism is not acceptable."