The child was taken to Airedale General Hospital by ambulance where he was pronounced dead.
A murder investigation was launched by West Yorkshire Police's Homicide and Major Enquiry Team and at 11:30am this morning and a 32-year old man was arrested from an address in the Ingrow area of Keighley.
More top news
A man accused of shoplifting has been banned from Toys R Us in West Yorkshire - even though the chain shuts for good in three days
The service, at Lincoln Cathedral, was ahead of a private funeral for corporal Jonathan Bayliss who died in a jet crash in Wales.
The singer is suing the BBC over its coverage of the police raid on his home.