The officers claim innocence of the 2008 death of the musician in custody in Brixton, London

The family of a man who died in police custody may suffer more delays in uncovering the truth as five officers facing a disciplinary hearing beginning on Monday morning are considering asking for the hearing to be scrapped, the Guardian has learned.

The Metropolitan police officers potentially face the sack over the 2008 death of musician Sean Rigg, 40, who died after being restrained.

Lawyers for the officers are considering telling the panel they cannot get a fair hearing after such a long period of time. The officers have protested their innocence and the case has been going on for so long one has retrained as a Church of England priest.

Parties to the inquiry expect the “abuse of process” argument to be raised. This would delay the start of the hearing and, if the officers were to win it, no hearing would take place at all.

The five officers are Sgt Paul White, PC Mark Harratt, PC Richard Glasson, PC Matthew Forward and PC Andrew Birks, the latter of whom is now a religious minister. He has been suspended from his police duties and is receiving his Met pay, but takes no salary from the Church of England.

Sean’s sister, Marcia Rigg, who has spearheaded the family’s decade-long fight against the system for investigating deaths in custody, said: “It is very important for the hearings starting on Monday to go all the way and to be heard in public throughout.

Met police sets 2019 date for hearings into death of Sean Rigg in 2008 Read more

“My family have had to fight every step of the way and it would be a travesty if we or the wider public are shut out while a room full of lawyers and police officers sit in secret to talk about Sean’s death.

“If I have to sit outside in a corridor while a panel decides any part of these gross misconduct charges in secret, including whether a full hearing is to take place, it will once more confirm for me that the system for police accountability in this country is not fit for purpose.

“A democratic state cannot allow significant charges of gross misconduct to be decided behind closed doors or cut short when only a full hearing held in public throughout is in the public interest.”

The police watchdog, the Independent Office for Police Conduct, had to use its legal powers to direct the Met to bring some of the charges. An IOPC spokesperson said: “I can confirm that the IOPC remains of the opinion that misconduct hearings for five officers in relation to the arrest and detention of Sean Rigg, and misconduct hearings for two officers in relation to evidence provided to an inquest into the death of Mr Rigg and the IOPC investigation, should take place.”

An inquest jury in 2012 found that police actions had contributed to Rigg’s death following his detention in Brixton, south London, after concerns were raised about the behaviour of the musician, who suffered from mental health issues. The inquest verdict followed a flawed first investigation by the then police watchdog, which exonerated officers, and which was subsequently overturned.

A source close to the five officers said their biggest concern was that “they get a fair hearing”.

Theresa May, while home secretary, was moved by the struggle of the Rigg family, and after meeting them and other bereaved families, promised action.

The Crown Prosecution Service has already decided that no criminal charges should be brought.