The video shows a young male lifting up furniture at the shopping centre and chucking it over the barrier on Saturday (March 1).
As it fell down, the furniture narrowly missed people walking on the floor below.
Days after the incident, police say they have launched an investigation after it was reported on Monday (March 3).
Inspector Dan Window, from Stratford Neighbourhood Policing Team, said: “Police are investigating after a heavy seat was thrown over a barrier from the first floor of Westfield shopping centre in Stratford on Saturday.
“The seating was reported to have narrowly missed members of the public below, fortunately there were no injuries.
“The matter was reported to police on Monday (March 3) and enquires continue.”
