The home secretary is to order an independent special inquiry into whether the Metropolitan police allowed hundreds of recruits to join without proper vetting amid fears they may pose a criminal risk.

The Guardian has learned that the inquiry will be carried out by the policing inspectorate, with concerns centred on 300 new officers hired between 2016 and 2023.

The recruits may have had substandard or no vetting before joining the Met and gaining police powers. Vetting is supposed to weed out applicants with criminal convictions, cautions or criminal associations or where their integrity is at risk because of debt.

Sources say an initial inquiry by the Met itself, called Operation Jorica began several months ago, and found potential issues with some officers hired between 2016 and 2023.

The Met is trying to show that its officers can be trusted after a series of scandals tarnished the reputation of Britain’s largest police force.

One officer, Wayne Couzens, who an inquiry found should never have been allowed into the force, abducted and murdered Sarah Everard in March 2021.

Another, David Carrick, used his position as a Met officer to instil fear in his female victims during a campaign of rape and sexual violence. Numerous complaints against him were not acted on.

The home secretary, Shabana Mahmood, and her officials have been kept informed on the Met review’s findings.

The independent inquiry will be carried out by His Majesty’s Inspectorate of Constabulary and Fire and Rescue Services.

The potential errors were picked up by the Met itself this year and revealed by the Guardian in September. Other forces may have made similar errors.

​The Met has been urgently revetting recruits whose appointment may have taken place during the seven-year period investigated.

The bulk of the recruitment happened during the police uplift programme, when the Conservative government hired 20,000 officers between 2020 and 2023, putting forces under pressure to recruit large numbers quickly. The Conservatives had cut police staffing by 20,000 officers in the previous decade.

The potential errors predate Mark Rowley’s appointment as commissioner in September 2022 and relate to when Dame Cressida Dick and her predecessor, Lord Hogan-Howe, were in charge.

In the three years since Rowley became commissioner about 1,500 officers have left during what he says is an attempt to clean up the force.

The force declined to say whether the vetting concerns have led to any officers resigning or being removed from duty via suspension or dismissal.

The Met said it did not wish to comment beyond its statement issued in September, which said: “We can confirm there is a review ongoing as part of our wider work on standards, vetting and professionalism. It is a review of vetting and hiring practices between 2016 and 2023.

“This is part of our determined effort to raise professional standards across the organisation and increase trust and confidence within our communities.”

A report commissioned by the Met from Louise Casey in October 2022 found flawed vetting and practices that allowed people suspected of serious criminal offences, including sexual assault and domestic abuse, to join or stay in the force.