Police are investigating the death of Maid Marian and Her Merry Men and Blackadder star Howard Lew Lewis.
Lewis died on January 20 at a community hospital in Edinburgh. He was being treated for dementia.
However, his daughter, Debora Milazzo, claims he had been placed on a regime of high-dose sedatives and maximum-strength opiate painkillers.
Milazzo told the BBC: "I'm trying to get justice for my dad. I want Police Scotland to investigate my dad's case."
She claims that her father had been unnecessarily placed on a treatment plan that would be used for the terminal phase of a malignant disease, even though he had not received a terminal diagnosis.
"My father didn't have cancer, he didn't have heart disease," Milazzo added. "They suddenly just changed his medication and it was the new medication that killed him."
Police Scotland confirmed that it was investigating the complaint. A spokesperson said: "Police in Edinburgh are investigating following the death of a 76-year-old man in the Carnbee Avenue area on Saturday, January 20.
"The death is being treated as unexplained, but not suspicious. A report will be sent to the procurator fiscal."
Dr Tracey Gillies, medical director of NHS Lothian Trust, said: "It would not be appropriate to discuss any details from his medical record.
"If the family have concerns or questions, they should contact us."
Lewis' credits include 1991 film Robin Hood: Prince of Thieves, and TV series Brush Strokes.
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