Two stained glass windows have been damaged at Boston Stump by people appearing to throw stones at the building on two separate occasions.
One of the windows was broken overnight on June 28/29, while the other was damaged in the early hours of July 4.
A spokesperson for Boston Stump said that the actions were a “senseless attack with the intent to cause damage to our wonderful building.”
Panes of glass were found smashed, causing significant damage that is expected to cost a lot of money to repair.
Sergeant Kate Odlin of Lincolnshire Police has asked for witnesses or anyone with CCTV footage to come forward.
She said: “It appears that someone has thrown stones at the window during the most recent act of criminal damage on July 3, leaving a number of holes in the window.
“These windows are of historical significance and this behaviour is totally unacceptable. We would ask anyone who may have any information to call us on 101.
“We are also asking local businesses to contact us if they have CCTV of this area on either June 28, June 29, July 3 and July 4.”
If you have any information that can help police investigations, call 101 and quote incidents 175 of June 29 and 243 of July 4.