France said he expected the IOPC to investigate “the whole range of what happened” and his force was committed to acting on the watchdog’s findings.
He added: “The officers who initially interacted with Henry are the same officers who started the CPR, who fought to save his life and I have no doubt of the extensive impact on the officers.”
The IOPC said: “Our thoughts and sympathies are with Henry Nowak’s family and everyone affected by his death.
“We are independently investigating the contact Hampshire and Isle of Wight officers had with Mr Nowak prior to his death on 4 December, including the use of handcuffs by officers and the first aid provided.
“Our investigation, which began following a mandatory referral from the force, remains ongoing and the officers involved are currently being treated as witnesses.”
Crime and Policing Minister Sarah Jones said: “This is a truly horrific case.
“All our thoughts are with Henry’s family and friends and what they are going through.
“We know that no verdict can undo the pain, but I hope today brings some small measure of justice.
“It is right that an IOPC investigation has been launched into the actions of the police to get to the truth.”
Digwa will be sentenced at Southampton Crown Court on Monday.