The police watchdog is "woefully under-equipped and hamstrung" and does not have the power or resources to get to the truth, a scathing report by an influential group of MPs has said.
The Independent Police Complaints Commission (IPCC), which is currently investigating the Hillsborough Disaster in the UK's biggest ever inquiry into police misconduct, should be given a statutory power to require a force to implement its findings, the Home Affairs Select Committee said on Friday.
And more cases should be investigated independently by the IPCC instead of being referred back to the original police force on a "complaints roundabout".
The watchdog, which was established in 2004 and is chaired by Dame Anne Owers, investigates the most serious complaints against the police, as well as the Serious Organised Crime Agency, Her Majesty's Revenue and Customs and the UK Border Agency.
A total of 31,771 officers were subject to a complaint during 2011/2012 and when appeals were made against the way forces handled a complaint, the IPCC found that the police had been wrong in one in three cases.
Committee chairman Keith Vaz MP said: "When public trust in the police is tested by complaints of negligence, misconduct and corruption, a strong watchdog is vital to get to the truth - but the IPCC leaves the public frustrated and faithless."
He added: "Nearly a quarter of officers were subject to a complaint last year. Many were trivial, but some were extremely serious, involving deaths in custody or corruption -it is an insult to all concerned to do no more than scratch the surface of these alleged abuses.
"The IPCC investigated just a handful and often arrived at the scene late, when the trail had gone cold. The Commission is on the brink of letting grave misconduct go uninvestigated."
The watchdog should have a statutory power to force implementation of its findings and in the most serious cases it should instigate a "year on review" to ensure that its recommendations have been properly carried out, the committee said.
Any failure to do so would result in an investigation by Her Majesty's Inspectorate of Constabulary and the local Police and Crime Commissioner, as a professional conduct matter relating to the chief constable.
The report said the IPCC lacks the resources necessary to "get to the truth" - it has a smaller budget than the Professional Standards Department of the Metropolitan Police alone.
IPCC investigators should be able to take immediate control of a potential crime scene during the crucial "golden hours" and early days of an investigation into deaths and serious injury involving police officers, the committee recommended.
The IPCC told the committee that a backlog of appeals had begun to build since the need to make financial savings had obliged it to reduce its complement of temporary staff.
As a result, the committee recommended that the Home Office develops ways in which a backlog might be cleared, such as through using temporary secondments of staff from other public authorities with relevant expertise.
The report said the cases involving serious corruption, such as tampering with evidence, should be automatically referred to the IPCC for independent investigation.
The government should maintain funding for anti-corruption cases at the same level committed to investigate the Hillsborough disaster.
Shadow home secretary Yvette Cooper said: "The Home Affairs Select Committee is right that the IPCC is not strong enough to tackle the problem when policing goes wrong.
"That is why I called for radical reform of police accountability last year, including replacing the IPCC with a new Police Standards Authority.
"For the public to have confidence in the high standards of British policing, they also need to know that there will be swift, robust action when policing goes wrong.
"Yet this report highlights a series of problems with the operations, powers, resources and support for victims within the current IPCC that the home secretary has not addressed."
In addition the committee said private firms - like G4S, Capita, Mitie and Serco - involved in delivering services that would once have fallen solely to the police should fall under the watch of the IPCC.
Scores of police officers including a serving chief constable are being investigated by the IPCC over the Hillsborough disaster.
The deputy chairwoman of the IPCC, Deborah Glass said that "without a shadow of a doubt" the probe would be the biggest investigation carried out into police behaviour in the UK.
A Home Office spokesman said: "Improving police professionalism and integrity are at the cornerstone of the sweeping reforms we are making to the police force, and the IPCC has a key role to play.
"We are already working to ensure the organisation has the powers and resources it needs to manage the challenges it is currently facing and we will shortly announce a package of new measures designed to further improve the public's trust in the police."