A man, believed to be 37 from London, who was found injured on the ground by police officers on patrol at 1.30am in Civic Square, Tilbury died this evening at about 8 30 pm.
He was in the company of a man and a woman who told police he had been assaulted in the toilets at The Anchor pub nearby.
The man was taken by ambulance to Basildon Hospital. A post mortem will take place in due course.
Anyone with any information is asked to contact officers at Tilbury CID on 0300 333 4444.