Police are appealing for witnesses after the incident, which took place in the Lidl supermarket on Musselburgh’s Newhailes Road at around 8.40pm on Saturday.
Officers said a 33-year-old Polish staff member was working on the till when he refused to sell alcohol to a male who appeared to be under the influence. The man began to shout offensive comments towards the victim and threatened him. He was then escorted from the store by other customers.
The man is described as white, in his fifties and over 6ft tall. He has short grey hair and was wearing a blue Adidas jacket. Inspector Andrew Harborow said: “We are keen to trace the customers who removed the suspect from the shop.” Those with information can call police on 101.