The PSNI have named the 14-week-old baby boy who died in hospital on Saturday.
He was Cameron Leslie from the Newtownabbey area of Belfast.
The little boy was admitted to the Antrim Area Hospital earlier this week to be treated for a number of injuries.
He was later moved to the Royal Victoria Hospital in Belfast, where he died yesterday.
Police have launched a murder inquiry and a 24-year-old man has been arrested for questioning.