The victim, Darren O’Neill, was named by police today.
He was punched on Tyrella Beach in Co Down at around 7.30pm on Thursday, Belfast Telegraph reported.
A 21-year-old man was charged in relation to the assault and is due to appear in court in July.
Detective Chief Inspector Darren McCartney said: “I would like to offer my sympathy to the family and friends of Darren at this very sad time.
“Our enquiries are ongoing to establish the full circumstances surrounding Darren’s death and I would appeal to anyone who may have witnessed this incident or who has any information to contact detectives on 101 quoting reference number 1913 27/06/19.”
MORE TO FOLLOW