Amanda Peterson died from an accidental drug overdose

TMZ reports the Weld County Coroner in Colorado, discovered she had a number of "prescription drugs in her system, including benzodizepines (anti-anxiety meds), opiates and phenothiazines (an anti-psychotic medication)".

She also had six times the recommended amount of the prescription drug Gabapentin in her system

The report stated that she was "naive to opiates" and also had recently taken marijuana and morphine medication.

Amanda's father previously told TMZ her family became worried when they didn't hear from her for two days.

He added: "She had some illness and a sleep apnea problem that may have contributed."

He added that she had other illnesses "including pneumonia and sinusitis [a common condition in which the lining of the sinuses becomes inflamed]".

Romantic comedy 'Can't Buy Me Love' tells the story of nerdy high-school student Ronald Miller, who pays a cheerleader (Amanda) to pretend to be his girlfriend for a month.

The film was directed by Steve Rash and named after the Beatles song.

Amanda's last movie was the 1994 fantasy/family film 'Windrunner' and she quit acting the same year before moving to Colorado.