Two men, one aged 26 and a second man aged 21,were arrested on suspicion of murder shortly after the incident.
The 26-year-old-man has been released under investigation and the 21-year-old-man has now been released with no further action.
Both these men suffered non-life threatening injuries during the incident and were treated at an east London hospital.
A third man, aged 33 was arrested on suspicion of murder at Heathrow Airport on Sunday, 7 July; he has now been bailed to return to a police station (date awaits).
Police were called to the Phoenix Club, Lea Bridge Road, E10 shortly before 3pm on Sunday, 7 July to reports of gunshots.
Officers, including firearms officers, attended and found a 27-year-old-man, who was from Stratford, E15, suffering from a gunshot injury.
Despite the efforts of officers and the London Ambulance Service (LAS) he was pronounced dead at the scene.
His next of kin have been informed, formal identification awaits.
A post-mortem examination will be held in due course and formal identification awaits.
The Homicide and Major Crime Command are leading the investigation.
Detective Chief Inspector Mark Wrigley who leads the investigation said: “We understand the victim and two other men had gone to the snooker club. The victim was then involved in an altercation with another group and a number of shots were fired. Now a man has lost his life, two others are injured and we need the community to support us and help bring those responsible to justice.
“I would appeal to anyone who was in or near the Phoenix Club to pick up the phone and call police now. Anyone with information about this brutal crime can contact the incident room, where detectives are ready to support you and take your call.”
Anyone with information can contact detectives at the incident room on 0208 345 3715 or via 101. You can also contact via Twitter at @MetCC, please quote CAD 1438/07JUL.