A burglar broke into All Saints church before tipping candlewax around the building and taking charity tins destined for the homeless and veterans.
The town centre place of worship and café had to remain closed yesterday as a result of the raid, such was the extent of the mess left behind.
Rector for All Saints Church, Father Oliver Coss, said the burglar, or burglars, only took items of minimal value from the church itself - a candle holder and alcohol from the café.
But donation tins belonging to the Royal British Legion, the Hope Centre and Cards for Good Causes were also taken.
"It's such a shame because all these charities are topical at the moment," said Fr Coss.
"The Hope Centre (a day centre for the homeless in Campbell Street) is very much in the press at the moment because of its eviction notice.
"The Royal British Legion is supporting veterans and Armistice Day is coming up.
"This has disappointed some very good causes."
Fr Coss said the church had to stay closed yesterday for a thorough clean.
"It looks as if they went walkabout with some of our candles," he said.
"The place was covered in candle oil, which has the consistency of crude oil.
"It was all over the building, so we had a good few hours cleaning up after the scene of crime police left."
Fr Coss said CCTV has been handed to the investigating officers and forensic evidence was taken from the scene.
If you have any information of the break-in, which happened overnight between Wednesday, November 7 and Thursday, November 8, call Northamptonshire Police on 101.