A member of staff at Homesense at Redlands in Poole, approached a man over concerns he was shoplifting.
It is reported the man became very aggressive towards the member of staff and was escorted out of the shop.
While leaving, he reportedly grabbed a shopping basket and threw it at the member of staff, causing injuries.
The incident happened at around 2pm on Monday, November 11.
Police Constable Lauren Meggs, of Bournemouth police, said: “As part of my enquiries, I have obtained a CCTV image of a man I would like to identify.
“I would ask anyone who recognises him to please get in touch.
“It is unacceptable for someone to be assaulted while doing their job and we are determined to identify those responsible.”
Anyone with information can contact Dorset Police at www.dorset.police.uk or by calling 101, quoting occurrence number 55240174969.
Alternatively, independent charity Crimestoppers can be contacted anonymously online at Crimestoppers-uk.org or by calling Freephone 0800 555 111.