Scotland Yard is expected to have spent more on policing the riots than it spent on policing all major public order events in the capital last year, officials said today.
The disturbances will cost the force more than £34 million, with the total expected to rise even further as the final bills from other forces called in to help is settled, the Metropolitan Police Authority (MPA) said.
This compares with a total of £34.8 million spent by Scotland Yard on policing 42 major public order events between April 2010 and March 2011, figures showed.
An MPA spokesman said: "The Metropolitan Police Authority expects at this stage that a figure in excess of £34 million is expected for policing the recent disturbances in London."
In comparison, policing the student fees protests in London cost Scotland Yard £7.5 million, while another £2.1 million was spent providing security at the TUC anti-cuts demonstration in March, £1.9 million on the Pope's visit to Britain, and £2.2 million around last year's general election campaign.
The figures were revealed as one chief constable said the rapid and robust justice dispensed in the wake of the riots has helped take the momentum out of the disorder.
Tim Hollis, the head of Humberside Police who was drafted in to help earlier this month, added that the swift action by the courts over the looting and violence raised questions over why cases usually take so long.
His comments came as magistrates rejected accusations from the leader of Britain's prison governors that there has been a "feeding frenzy" in sentencing after the recent riots.
Writing in the Yorkshire Post, Mr Hollis said: "We witnessed an unusual but very welcome degree of co-operation and support from our partners in the criminal justice system.
"We really did see rapid and robust justice with offenders being arrested, charged, put before the courts and sentenced in days.
"This undoubtedly contributed to taking the momentum out of the disorder - but for the police and public it did raise the question as to why cases take so long to get to court in the normal course of events."
He also questioned "why imprisonment is not used more effectively at an early stage for those who make the lives of the law-abiding a misery on a more routine basis".
But Eoin McLennan-Murray, president of the Prison Governors Association (PGA), claimed over the weekend that magistrates had lost all sense of proportion.
"It's like when you've got sharks and there's blood in the water and it's a feeding frenzy," he told The Independent on Sunday.
"There's a sentencing frenzy and we seem to have lost all sight of proportionality.
"It's appealing to the populist mentality, and that's not the best basis on which to sentence people. The norms of sentencing are being ignored."
But Magistrates' Association chairman John Thornhill said the claims were "unreasonable and unfounded", adding that it was "just not the case" that normal sentencing was being ignored.