FROM MAIL ONLINE - He is wrestled to the floor as he appears to try to swallow an item. The policeman can be seen holding his hand briefly over the Mr Charles' mouth.
As the suspect struggles on the floor, a bystander in to help the policeman with the arrest. After they put the handcuffs on, it appears the man has stopped breathing and the officer removes his hat as he radios for help.
Moments later, two more officers arrive on the scene and the video is cut off.
Police and the IPCC said the man was pronounced dead at the Royal London Hospital but would not comment on whether he stopped breathing beforehand.