Police are appealing for witnesses following reports that a man had been assaulted while on Southend Road, Grays around 12am on Monday 30 November.
Officers received reports of an altercation between a group of men, which resulted in a man sustaining life-threatening injuries.
A 26-year-old man from Grays has been arrested in connection.
The road remains closed whilst officers conducted their investigation.
Police would like to speak to anyone who was in the area around this time and saw any suspicious or unusual behaviour.
They are also keen to hear from anyone who has doorbell, CCTV, or dash cam footage which captured what happened.
Anyone with information is asked to call 101.
Please reference incident 49 of 30 November when providing any information to ensure it gets to the investigating officer as quickly as possible.