The Metropolitan police has been ordered to schedule gross misconduct hearings for five officers over the death of Sean Rigg, whose heart stopped at a south London police station 10 years ago after prolonged restraint.

The Independent Office for Police Conduct told the force to bring proceedings against the officers, including for allegedly failing to identify and treat the 40-year-old as suffering from mental health problems, failing to protect him from harm, and failing to treat him once it became clear he was ill.

However, one officer may yet escape after he successfully challenged the grounds of his suspension from the Met. PC Andrew Birks, who has been suspended on full pay since 2014, could now apply to retire from the force, putting him beyond the reach of its disciplinary process.

At the high court on Friday, Mr Justice Garnham said Birks’ suspension “cannot stand” because the assistant commissioner did not take into account the lengthy delay in deciding whether he should face any charges.

Birks, who was ordained a priest in the Church of England last year, will still have to wait to find out if he will be allowed to resign, as the judge ordered that the decision should be taken afresh in light of his ruling.

Sarah Green, regional director of the IOPC, directed the Met to bring the charges against the five officers last month, but her decision was kept private while the court considered Birks’ legal challenge.

“As a result of today’s judgment, the disciplinary process against PC Birks is stayed pending reconsideration of the decision by the assistant commissioner of the MPS to suspend him,” said Green, adding that she would make representations to the Met on the issue.

The IOPC has already forced the Met’s hand over separate disciplinary proceedings against two of the five. Sgt Paul White and PC Mark Harratt will face a hearing over claims they gave misleading evidence to an inquest jury and to IOPC investigators.

They will now be joined by PCs Richard Glasson and Matthew Forward, and potentially Birks if the Met confirms his suspension, in facing the new charges. In February White also attempted to retire, but was blocked by senior officers.

Rigg, who had paranoid schizophrenia, was living in a hostel in Balham, south London, in 2008. Police were called after he allegedly smashed up a gazebo and made karate moves that staff found threatening.

In 2012, an inquest concluded that police restrained him . Officers left him in the van, unmonitored and hands bound behind his back, for 10 minutes before bringing him to the caged entrance to the cells. It was there that he suffered a cardiac arrest and died.

The inquest jury found that police had used unsuitable and unnecessary force on Rigg, and failed to uphold his basic rights. But in 2017 the Crown Prosecution Service decided not to prosecute any of the officers, despite receiving a dossier of evidence from the Independent Police Complaints Commission, the forerunner of the IOPC.

Rigg’s sister, Marcia Rigg, called on the Met to “do the right thing” and re-suspend Birks so that he must face disciplinary proceedings, which she said were the last opportunity for the officers involved in her brother’s death to be formally held to account.

“My family and I welcome the IOPC’s decision to direct gross misconduct charges for officers involved in Sean’s death,” she said. “As we approach ten years since my brother died following unnecessary and unsuitable restraint, we hope that the hearings will take place as soon as possible and provide some much-needed accountability.”

Deborah Coles, executive director of Inquest, which has supported the Rigg family, said: “The delay and obfuscation in this case has had a punishing impact on Sean’s family, who have fought tirelessly for justice for Sean, and indeed for many other families, over the last decade.

“The delays not only impact families, but frustrate and weaken the processes intended to bring truth, accountability, and policy change. The Metropolitan police’s commitment to accountability for a preventable restraint related death will be judged by their response to this judgment.”

• This article was amended on 14 April 2018 to clarify a number of details.

