The emergency services were called to Liverpool Street around 1.15am today (June 11).
Paramedics treated a man with a leg injury before taking him to hospital “as a priority”.
Liverpool Street remains closed by police while a crash investigation is underway.
Pictures show forensics working in the area behind police tape.
City of London Police has been contacted for more information.
A London Ambulance Service spokesperson said: “We were called at 1.16am today (11 June) to reports of a road traffic collision on Liverpool Street.
“We sent resources to the scene, including an ambulance crew, an incident response officer, a paramedic in a fast response car and an advanced paramedic.
“We treated a man for a leg injury and took him to a major trauma centre as a priority.”
