Scotland Yard is considering whether to launch a criminal investigation into claims the Independent Police Complaints Commission deliberately suppressed evidence during an inquiry into alleged police misconduct.
Three police officers were cleared at a misconduct hearing in July and have lodged a criminal complaint with the Met about the conduct of the IPCC.
Scotland Yard said it was “assessing” information relating to “two linked allegations of crime”. The IPCC said it was “aware” of the allegations.
The IPCC has previously apologised for failings in the way it dealt with the case,
It concerned a black firefighter, Edric Kennedy-Macfoy, who was Tasered by police during a disturbance at Harrow, north-west London, in September 2011.
The fireman claimed he had been assaulted and racially discriminated against by police.
Last year, the Metropolitan Police apologised and paid him compensation to settle a civil claim he had brought against the force.
Three months ago, as a hearing was due to start against three policemen accused of gross misconduct, their legal teams say they received material that had not previously been disclosed.
It allegedly contained accounts from eyewitnesses, including other police officers and bystanders.
The IPCC withdrew from the case and the officers were formally cleared.
At the time, the watchdog issued an apology to Mr Kennedy-Macfoy and the officers saying that it had identified “procedural shortfalls”.
It said they “related to disclosure of relevant material and the need for further investigative work, including witness interviews, which it became clear were not conducted during the investigation”.
The organisation set up an “in-depth review” headed by the Northern Ireland Police Ombudsman.
However, the police officers have made a formal complaint alleging the IPCC deliberately withheld evidence and that criminal offences may have been committed.
The IPCC commissioner in charge of the misconduct investigation into the police officers was Jennifer Izekor.
In a statement commenting on the allegations made by the officers about the IPCC, Ms Izekor said: “I am confident that these allegations are without foundation.
“It would be inappropriate to say more at this stage.”
Scotland Yard said: “We can confirm that in September the MPS [Metropolitan Police] received two linked allegations of crime, relating to issues arising from a misconduct hearing in July 2016 which was halted because of issues with disclosure.
“The allegation [sic] has been recorded and is being assessed,” the force said, although it did not specify against whom the complaints had been made.
An IPCC spokesman said: “The MPS has made us aware that two linked allegations are being assessed and as such it would be inappropriate to say more at this stage.”
If an investigation were to be launched, it is thought it would be the first time that a police force had examined criminal allegations made against the police watchdog.
John Downes, the lawyer representing the officers, said their lives had been “tarnished” by the misconduct allegations.
“We welcome the news that officers from Scotland Yard are assessing the criminal claims against the IPCC. My clients have suffered for the past five years since the original incident.
“They now hope the allegations they have made against the IPCC are taken seriously by the Metropolitan Police and look forward to being updated soon.”