An American priest and prison chaplain in northern Mexico says his home, which doubles as a halfway house, was raided in the early hours of St Patrick's Day as police came to arrest one of the three men who live with him.

Fr Robert Coogan, a New York native, also alleges that the police tried to plant drugs during the raid, part of a pattern of harassment against the former prisoners whom he helps transition from spending time behind bars to leading productive lives.

"Since we opened the house, there has been harassment," said Fr Coogan, who works in Saltillo, about 190 miles from the Texas border. He said if there is a problem in the neighbourhood, people blame house residents.