Officers say that at some point between midnight on March 30 and 9.30am on April 2 an unknown offender forced entry into Eye Town Hall in Broad Street.
The offender then set off a fire extinguisher and damaged a number of paintings inside the hall.
A man was captured on CCTV wearing baggy trousers, and a coat with a fluorescent logo outside the front steps of the town hall on April 1 at 10.20pm.
He left the area at around 10.45pm and police say they think he may be able to assist with the investigation.
Anyone who recognises the man in the CCTV pictures should contact Suffolk police on 101, quoting crime reference 17763/18 or call Crimestoppers anonymously on 0800 555111.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here