Detectives from Central East Command Unit are investigating an attempted murder.
Police were called at 22:34hrs on Tuesday, 19 November to Nelson Street, E1 to reports of man collapsed in the street with a head injury.
Officers and the London Ambulance Service attended and administered first aid and the 40-year-old man was taken to hospital.
His next of kin have been informed.
The injury to the victim’s head is strongly suspected to be the result of a bullet wound and his condition is described as critical.
There have been no arrests.
A forensic scene is in place and enquiries continue.
Any witnesses or anyone with any information is asked to call the police incident room on 0208 345 3775. Alternatively call 101 or contact via Twitter @MetCC. Please quote CAD 10007/19 NOV.
To give information anonymously contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.