A thief stole a charity box containing around £50 for the East Anglian Air Ambulance.
The incident happened at around 7.45pm on March 13 at the Wortley Almshouses in Westgate.
Police have released CCTV images of a man they would like to speak to in connection with the theft.
PCSO Matt Lauch said: “I am appealing for anyone who may know the man in the CCTV images to contact police as I am keen to speak to him.”
Anyone with information is asked to contact police on 101 or Crimestoppers, anonymously, on 0800 555 111, or via their online reporting system at www.crimestoppers-uk.org.