A probe has been launched after a 93-year-old disabled man was pepper sprayed and Tasered by police at a care home.
Donald Burgess died in hospital three weeks later.
Police had tried to detain Mr Burgess, who was wheelchair-bound, had one leg and suffered from dementia, following a report he had threatened care staff with a knife.
Two officers from Sussex Police attended the home, in St Leonards-on-Sea, East Sussex, on 21 June
One of them used Pava spray, which is similar to pepper spray, while the other deployed a Taser. The knife was then removed from Mr Burgess and he was handcuffed.
He was taken to hospital, where he remained until his death three weeks later on 13 July.
Police watchdog the IOPC is investigating and gross misconduct notices have been served on the two officers involved, both police constables, with letters advising them they are under criminal investigation for manslaughter.
The IOPC says these actions do not necessarily mean disciplinary proceedings or criminal charges will follow.
Cause of Mr Burgess’s death not known yet
The Independent Office for Police Conduct (IOPC) is investigating whether the allegations of use of excessive force by the officers amount to criminal manslaughter after Sussex Police referred itself to the watchdog.
IOPC regional director Graham Beesley said: “I want to express my sympathies to the man’s relatives and those who knew him.
“We have advised his next of kin of our independent investigation and explained the steps we will be taking.
“This will include investigating whether the force used by the two officers against this male was reasonable, necessary and proportionate in the circumstances and in line with local and national policies, procedures and guidance.”
So far the IOPC investigation has included taking witness statements, reviewing the officers’ body-worn footage, and attending the post mortem examination on July 21. The cause of Mr Burgess’s death is not yet known.
A spokesman for Sussex Police said its investigation is still ongoing.
Assistant Chief Constable Tanya Jones, of Sussex Police, said: “We want to express our sympathies to the family and friends of Mr Burgess. Our thoughts remain with them at this difficult time.
“We are providing every assistance to the IOPC to allow for a thorough investigation and for the family to receive the answers they need.”