The head of the police complaints watchdog will give evidence to the Commons on the G20 protests.

Nick Hardwick, chairman of the Independent Police Complaints Commission (IPCC), will give evidence to the Home Affairs Select Committee after saying he had "serious concerns" about frontline supervision of officers at this month's G20 demonstrations.

He said police needed to remember that they were "servants, not masters" of the people.

The IPCC launched its third investigation into police tactics on Saturday after a 23-year-old London man claimed he was assaulted by a Met Police officer.

The commission is already investigating events leading up to the death of newspaper seller Ian Tomlinson on April 1, and an allegation of an assault on Nicola Fisher at a vigil for Mr Tomlinson on April 2.

The Select Committee will also hear from Her Majesty's Chief Inspector of Constabulary Denis O'Connor.

Keith Vaz, the Labour chairman of the Home Affairs Select Committee, said MPs would examine the controversial "kettling" tactic used to contain demonstrators.

Mr Vaz said that MPs "will obviously want to look at what happened at the G20 protests" and the scope of the IPCC investigation.

He added: "I have faith in the IPCC, I think it's important that we have an independent body that looks into complaints against the police and we don't rush to judgment."

The president of the Association of Chief Police Officers, Sir Ken Jones, defended police tactics used at the G20 demonstrations as "proportionate" and recent criticisms had lacked objectivity and perspective.

"We need to make sure we don't condemn the many for the problems created by a few," he said.

An IPCC spokesman said more than 185 complaints had been received relating to G20 of which almost 90 were from alleged victims of - or witnesses to - excessive police force.

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