The incident happened at approximately 5pm on Wednesday, May 11 after a staff member at the pub in Queens Road asked the man to leave.
He reportedly punched the staff member in the groin as well as the side of his face. The victim did not require hospital treatment.
Dorset Police are appealing to the public for help in identifying the man.
Police Constable Russell Thomas, of Bournemouth police, said: “Following initial enquiries into this incident, I have obtained a CCTV image of a man I would like to identity.
“If anyone has any information about his identity, please get in touch with Dorset Police.”
Anyone with information is asked to contact Dorset Police at www.dorset.police.uk/contact, via email email@example.com or by calling 101, quoting occurrence number 55220074807.
Alternatively, independent charity Crimestoppers can be contacted anonymously online at Crimestoppers-uk.org or by calling Freephone 0800 555 111.
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