United Kingdom, Aug. 17 -- Hayden Panettiere's on-off boyfriend spoke candidly about their troubled relationship and why they were unlikely to get back together in what became one of his final interviews about the actress before her sudden death at 36.

The Heroes and Nashville star was found unresponsive at a residence in Greenville, South Carolina, on Sunday, 16 August, after an acquaintance called 911 at about 1.51pm.

Emergency crews found Hayden in cardiac arrest and attempted advanced life support before she was pronounced dead at 2.32pm.

An autopsy has since found no signs of trauma contributing to her death, while her cause and manner of death remain pending further testing.

Dispatch audio obtained by TMZ included references to ...