Detectives investigating the shooting of German Gorbuntsov continue to appeal for information to trace a suspect.
The suspect described as white, 6ft tall and of slim build, and wearing a dark hooded top was seen running from Byng Street away from Westferry Road, believed through Bellamy Close, towards the Marsh Wall area.
Officers now believe the weapon used in the shooting was a pistol.
Police were called at approximately 7.30pm to reports of the shooting.
Mr Gorbuntsov was shot a number of times as he entered a block of flats.
Officers and London Ambulance Service attended and the victim was taken to hospital. His condition is described as critical but stable.
Detectives from the Trident Gang Crime Command are investigating and are treating the shooting as attempted murder. They are keen to speak to anyone who was in the area at the time or who may have information about the incident.
They are still keen to speak to the driver of a Hackney cab, who they believe picked up the victim, 45, in the area of Bishopsgate, EC2, at around 7pm before dropping him off in Byng Street, E14, shortly before 7.30pm.
The shooting is not thought to be gang-related or linked to any other incidents in Tower Hamlets. Officers retain an open mind regarding the motive for the attack at this time.
Any witnesses or anyone with information can call the incident room on 020 8733 4212; if you wish to remain anonymous please call Crimestoppers on 0800 555 111.
There has been no arrest at this time and enquiries continue.