A major report examining how the G20 protests were policed is due to be published.
Denis O'Connor, HM Chief Inspector of Constabulary, has looked at public order tactics used on the day that newspaper vendor Ian Tomlinson died.
His report is likely to look at controversial "kettling" techniques.
They were used to keep thousands of protesters inside cordons in the City of London on April 1.
Critics say they restrict movement and can increase tensions between demonstrators and officers.
Mr O'Connor has already criticised officers who do not wear their police numbers.
He told the Commons Home Affairs Committee earlier this year that some officers had behaved "unacceptably" during the protests.
He said: "My concern was obviously about the individual incidents where officers, on the face of it, appeared to break with their colleagues and assault people.
"We in this country expect the very best from our police, quite properly, and police officers who give their lives - as Gary Toms did, sadly, very recently - they do it for a very noble cause. So when you see something that does not square with that noble cause, it is disappointing and hugely concerning."
The report will not look at individual complaints against police officers which are being investigated by the Independent Police Complaints Commission.