The CCTV images show three electric scooter riders on Downshire Way, Bracknell.
The images are from the night Agapito de Sousa was attacked on Sunday, April 25 at around 3.30am.
Police say the riders on scooters are heading towards the direction of the Twin Bridges underpass.
Officer also believe the people in the CCTV images have vital information as part of their murder investigation.
Agapito de Sousa, 34, was taken to hospital but sadly died from his injuries on Tuesday, April 27.
Senior Investigating Officer, Detective Chief Inspector Stuart Bosley from the Major Crime Unit said: “These images are not of a high quality, but we are very keen to hear from the riders of these scooters, who were seen on CCTV entering the underpass on the morning of 25 April.
“I would like to stress that at this stage, we believe these individuals to be witnesses, but we have, as yet, been unable to identify them, and would urge them to please contact Thames Valley Police, as it is possible that they may have seen the incident, or have some information that may prove crucial to our investigation.
“If you believe any of these individuals are you, I am urging you to please contact us so that we can ascertain whether you have any information or witnessed what happened.
“Similarly, if anybody does recognise them, please get in touch with us.”
The community has also been told that this was an isolated incident and there is not believed to be any wider threat to the public.
Police said they are trying to figure how what happened on the night Agapito was attacked to bring answers to his family.
So far, a 39-year-old man from Bracknell has been arrested on suspicion of manslaughter and theft. He has been released under investigation.
Police added: “This is a complex investigation, and I would like to again express my thanks to all those who have come forward so far to assist us.
“We remain resolute in our determination to ascertain the circumstances that led to Mr de Sousa’s death and will leave no stone unturned in our investigation.”
If you have any information call Thames Valley Police on 101, or make a report online, quoting reference number 43210174782.