Detectives investigating the death of Terry Leeks in Basildon want to identify four people who they believe may be witnesses.
Mr Leeks, 46, died after being stabbed in Northlands Park at around 1.30am on Sunday July 11.
Police want to identify four people who were captured on CCTV in the Lincoln Road area at around the time of the attack.
Seven people arrested on suspicion of murder are currently on bail and a woman has been arrested on suspicion of assisting an offender.
Detective Chief Inspector Louise Metcalfe, from the Kent and Essex Serious Crime Directorate, is leading the investigation and said: “These four people were in the area at the time of the murder, they may have seen something which could be important.
“I need to identify them and speak to them to find out if they have saw or heard anything.
“If you recognise any of them, or you are one these men, please contact my team.”
If you recognise any of the men pictured, or if you are one them, please call 101 quoting the crime reference number 42/136379/21.
Police are continuing to appeal for anyone who saw what happened, has any CCTV, dash cam or doorbell footage, or any other information to come forward.
You can submit a report online at https://www.essex.police.uk or use the ‘Live Chat’ button to speak to an online operator between 7am-11pm.
You can also call 101 or contact Crimestoppers anonymously on 0800 555 111.
If you contact Crimestoppers they don’t ask your name or any personal details, they don’t record your call and your number is never displayed.
When information is passed to the police, it doesn’t contain any information which could identify you.