Two teenagers have been arrested for theft and assault at Tesco in Katherine Place, Abbots Langley.
At around 7.50pm on March 25, a member of staff challenged a female, the suspected shoplifter, who he believed had stolen a bottle of prosecco.
He followed her outside of the store and while attempting to stop her he was approached by a large group of boys who had already been asked to leave the store.
The victim was reportedly punched in the jaw causing him to lose consciousness.
Three boys; two aged 14 from Watford and one aged 15 from Essex were arrested on suspicion of assault.
They have been released under investigation while enquiries continue.