Police were called to Valley Farm Caravan Park, in Valley Road, at around 9.15pm on Wednesday, October 14, following reports of a man making threats.
Officers attended and found a man in his 40s, from Frinton, injured inside a caravan.
Despite the emergency response, the man was pronounced dead at the scene.
Specialist officers are supporting his family.
Essex Police said a 39-year-old man from Ingatestone was arrested on suspicion of murder.
Entrance to Valley Road Caravan Park (Image: Supplied)
He was taken to hospital for treatment to an injury to his hand.
Police said it was also reported that an officer was assaulted while responding to the incident.
The 39-year-old was subsequently further arrested on suspicion of assaulting an emergency worker.
Detectives believe the two men were known to each other and have said they are not looking for anyone else in connection with the incident.
Detective Inspector Tim Coyles said: “My thoughts this morning are with the family of the man who died last night.
“We will work tirelessly to get them the answers they need about what happened.
A cordon remains in place (Image: Supplied)
“We have already made good progress at building a picture of what took place and, at this stage, we believe both men were known to each other.
“We are not looking for anyone else in connection with this incident, and we don’t believe there is an ongoing risk to the wider public.
“I believe there will be a number of people who saw or heard something last night that may be helpful to our investigation and I urge them to come forward.
“Officers will be carrying out enquiries at the site throughout today.”
Anyone with information which could help the investigation can submit it through Essex Police’s dedicated public portal.