At around 4.30pm on Friday, June 29, a man entered the Nationwide building society in George Street, Luton, and handed a note to staff stating he had a knife and would use it to harm customers if they did not hand over cash.
The man was chased by staff and ran off in the direction of Upper George Street.
Detective Constable Tracey Joyce, investigating, said: “We are keen to speak to a man in the footage, as we believe he may have information that could help our investigation.
“If you recognise the man, please get in touch. It was a frightening incident for the Nationwide staff, and such activity won’t be tolerated in our county.”
Anyone with information about this incident or anyone who recognises the man is asked to call 101 quoting reference number 334 of 29 June.
Alternatively you can contact Crimestoppers anonymously on 0800 555 111.