A couple who were yesterday described as "key witnesses" in the James Attfield murder case have come forward.
Officers reissued their appeal for them to get in touch yesterday morning and last night the man contacted the incident room.
A spokesman said: "Detectives investigating the murder of a man in Colchester believe they have now identified a man and woman recorded on CCTV and so will be looking to eliminate them from the investigation.
"They will be spoken to after which detectives will then be able to ascertain whether they are also the couple seen on the bench at 11:30pm on Friday, March 28.
"Furthermore, the man shown in Image 15 (02:36:31) has also contacted police and will look to also soon be eliminated from enquiries.
"This leaves eight people still to be identified from the CCTV."
Mr Attfield, known to his friends as Jim, was found seriously injured with over 100 stab wounds in Castle Park off Guildford Road shortly before 6am on Saturday, March 29.
He died a short time later at the scene.
The 33-year-old man from East Bay in the town was last seen in the River Lodge Public House on Middleborough on Friday, March 28.
He left there shortly after 10pm, but detectives are still trying to trace his movements in those hours before his death.
A Crimestoppers reward of up to £5,000 still remains on offer for information which leads to the arrest and conviction of the person or people responsible for the murder.
Anyone with information is asked to call Essex Police on 101 or Crimestoppers anonymously on 0800 555111.
A man and a woman, both aged 27 and from Colchester, are currently on police bail until Wednesday, May 21 after having been arrested in connection with the murder.