A man in his 50s collapsed and died at a property in Great Waldingfield on Friday evening.
Despite the efforts of the emergency services, the man was pronounced dead at the scene at a house in Green Acre.
A spokesman for the East of England Ambulance Service said an air ambulance helicopter, rapid response vehicle, road ambulance and a community fast response car attended the incident.
Paul Middleton, who lives in High Street, witnessed the air ambulance helicopter attending.
“I saw the Essex and Herts Air Ambulance helicopter land on a small field next to Great Waldingfield Bowls and Social Club in Tentree Road,” he said.
“Four paramedics then walked through into a garden of a house in Green Acre where I believe someone was lying outside.
“The medics returned about 20 minutes later without a patient and the helicopter took off.”
Police are not treating the death as suspicious.