Officers are calling for anyone who saw what happened at Bath Central United Reformed Church in Argyle Street last week to get in touch.
Crew members from Devon and Somerset Fire Service were called to the scene at approximately 3am on Wednesday 8th November.
It appears that the belongings of a rough sleeper were set alight before the flames spread to the doors of the church, causing damage.
Photos reveal scorch marks left on two exterior walls of the building, and the extent to which the green-painted doors were left blackened by the fire.
In a statement, Avon and Somerset Constabulary said: “It’s possible that a passing taxi or delivery driver, or a person on their way to work, may have witnessed the offence.”
Anyone with information should call 101 and quote reference 5217255283.
Police have released images of damage caused to a church in Bath during an arson attack, as they appeal for witnesses.