Last modified on Thu 25 Feb 2021 23.37 EST
Five police officers are under investigation for manslaughter after the death of a 24-year-old man in police custody earlier this month.
Brian Ringrose, from Milton Keynes, was placed in an induced coma and died in hospital days after he was arrested by Thames Valley police on 27 January.
The Independent Office for Police Conduct said it was investigating the use of a “flexible lift and carry system” (Flacs) used to transport Ringrose to a police van when he was restrained using handcuffs and limb restraints.
The Guardian has requested more information from the National Police Chiefs Council on what Flacs is and how it is used.