In her evidence to the inquiry, Ms Coles said the "lack of candour" on the part of mental health trusts in Essex was the reason a statutory public inquiry needed to be held.
"It's difficult to say how traumatising that is for families when they sit in at an inquest… and then see legal representatives try and effectively stop a coroner from making a Prevention of Future Deaths report, which is ultimately about trying to safeguard lives in the future - and I find that reprehensible," she said.
"We are talking here about trying to protect lives and also remember those who've died where those deaths were preventable."
