(CNN) -- The December death of a 27-year-old woman at the Missouri home of beer tycoon August Busch IV was ruled an accident, a medical examiner said Wednesday.
Adrienne Nicole Martin died of an oxycodone overdose, the St. Louis County Office of the Medical Examiner said in a statement. She was found dead December 19 at Busch's Frontenac, Missouri, home, authorities said.
The medical examiner's office said that information, and its complete report, was forwarded to the law enforcement agencies investigating Martin's death.
Police responded to a call from the home about an unresponsive woman, authorities said.
"This girl is not waking up," Michael Jung, a home staff employee at the Busch estate, told the operator.
"Is she breathing"? the 911 operator asked Jung.
"We don't know," Jung replied. "It's dark. I'm going to get a light to see." The call ended after the operator told Jung an ambulance had been sent to the property.
Martin had no apparent signs of trauma or other indications of cause of death, police said.
Oxycodone is a narcotic pain medication.
Busch's lawyer, Art Margulis, described Martin as a friend of his client's.
"There's absolutely nothing here that would indicate that this occurred under any suspicious circumstances," Margulis said at the time. "It's a tragic death of a ... very nice young lady."
Frontenac, a community of about 3,500 people, is 11 miles west of St. Louis.
Martin was a model and aspiring art therapist, described as Native American on her page on iStudio.com, which says it serves "the modeling, photography, and associated industries." In the About Me section of her page, she wrote that she had been in beauty pageants for years and "would really like to do beer advertising."
Busch, 46, became chief executive officer of Anheuser-Busch in December 2006, after years of working in the company's brewing, operations and marking divisions. He was in charge in 2008 when Belgian brewer InBev engineered a $52 billion takeover of the then-St. Louis-based, company. With that move, the combined Anheuser-Busch InBev became the world's largest brewer.
That also largely ended the Busch family's long legacy in brewing, namely heading the legendary eastern Missouri institution known for its Budweiser and other brands. The story started with Adolphus Busch, the company founder and August Busch IV's great-grandfather.
August Busch IV is the only representative of the family -- and its former namesake company -- on the Anheuser-Busch InBev board of directors.