"But not only have they disrespected her father while he was alive, they've done it when he's dead," Sainsbury said.
Heritage Lifecare, the parent company of Palms Lifecare, had launched an investigation into the original complaints but its executive chairman said he did not believe there was anything wrong with the way staff had handled the body.
Executive chairman David Renwick said the man's body was left in the bed so the doctor could certify the death.
His body may have been there slightly longer than if he had died during the day, he said.
"This process can take several hours to complete depending on the time of day death occurs and the doctor's availability.
"The body is respectfully laid ready by staff for collection and for the family to view."
They were half-way through its investigation regarding the initial allegations and would share the findings with everyone at its close, Renwick said.
He was confident the man had been treated with "dignity and respect" in his final hours.