Eminem, whose real name is Marshall Mathers, adopted his sister-in-law's daughter, Alaina. Reuters

American rapper Eminem has been devastated by the news that his sister-in-law has died of a drug overdose in a trailer park near Detroit.

Police said Dawn Scott, 40 — the mother of Eminem's adopted daughter, Alaina — was found unresponsive in a unit of the Motor City Trailer Park on 18 January in Warren, a short distance from the hard-scrabble neighbourhood where she and the famous rapper grew up on Detroit's tough 8-Mile Road. Warren officials said Scott died of "an apparent heroin overdose, pending a toxicology test."

Scott just months ago complained to Radar Online that the millionaire rapper and his ex-wife, Kim Mathers, Scott's twin sister, were "refusing to give me any help." It's "a betrayal. He's been part of our family since he was 15," she said of Eminem.

But friends described the homeless woman as a hopeless addict who would take any kind of pill she could find to stave off withdrawal.

Scott was "doing any kind of drugs she could get her hands on," her ex-boyfriend, Les Martin, told Radar Online. "Heroin, cocaine, Adderall. If it was a pill, she would take it. Klonopin were her downfall. She was swallowing them things like candy."

Scott and her sister moved in with Eminem (before he became famous) when they ran away from home at the age of 15. Eminem and Kim Mathers divorced in 2001 after a tumultuous relationship that was fodder for Eminem's raps.

Eminem has had his own serious struggles with addiction, most notably to prescription pills, and has talked about it in his album Recovery and in the documentary How to Make Money Selling Drugs.

The problem spiraled out of control as he began mixing pills — "Xanax, Valium, tomato, tomatoe, it's same thing ... take it," he said in the film, and one day was rushed to the hospital in critical condition. "Had I got to the hospital about two hours later, I would have died. My organs were shutting down," he recalled. "They didn't think I was gonna make it. My bottom was gonna be death." He says he finally got clean through a self-imposed detox, driven by his desire to be a good father.