A man collapsed and died during G20 protests, London Ambulance Service said last night.

Emergency services were called at 7.24pm by a member of the public who found the man unconscious in the street.

Police officers arrived at the scene first, but the man had stopped breathing.

An ambulance service spokesman said: "Our staff immediately took over the treatment of the patient and made extensive efforts to resuscitate him both at the scene and on the way to hospital."

He died in hospital.

A Metropolitan Police spokesman said: "A member of the public went to a police officer on a cordon in Birchin Lane, junction with Cornhill to say that there was a man who had collapsed round the corner.

"That officer sent two police medics through the cordon line and into St Michael's Alley where they found a man who had stopped breathing."

Police moved him to an area outside the Royal Exchange Building where they attempted resuscitation.

The spokesman added: "The officers took the decision to move him as during this time a number of missiles - believed to be bottles - were being thrown at them."

According to one protester at the scene the man was in his 30s and died of natural causes.

The Directorate of Professional Standards at both the Metropolitan Police and City of London Police have been informed.

The Independent Police Complaints Commission will also be notified.