The victim, a man in his late 50s, was assaulted at the Scotland Green bus stop on Tottenham High Road, N17, sometime before 10.45pm on Friday, 28 August.
Officers have not been able to determine further details as shortly after returning home following the incident, the victim suffered a heart attack and remains in hospital in a critical condition.
Detective Constable Jane Fluckiger said: “Unfortunately we do not have any descriptions of suspects or even the exact time frame for this offence as the report was made via a third party. However, the victim returned home with cuts on his face stating he had been robbed by two males at Scotland Green bus stop and therefore it is possible the incident happened between 21.00hrs and 22.30hrs.
“If you know what happened, or even if you think you saw anything suspicious or out of place, please call us without delay, or report what you know anonymously via Crimestoppers.”
It is not known at this time whether any items were taken from the victim during the incident.
If you have any information that could help with this investigation then please call the police on 101 quoting ref CAD7929/28AUG20.