Washington, June 28 : Investigators probing into the cause of Michael Jackson's death are trying to determine whether or not prescription drugs may have played a role.

The L. A. coroner says that it will take weeks to confirm the cause of death.

However, still, some newspapers have cited unnamed sources and declared that the `Thriller' star took a daily cocktail of narcotics, including Demerol, Dilaudid, Vicodin, Zanax and Paxil.

A pharmacy in Beverly Hills sued Jackson two years ago, claiming the entertainer owed more than $100,000 for prescription drugs.

J. Randy Taraborelli, a biographer, said that family and friends concerned for years.

"It''s been a long, ongoing problem," CBS News quoted Taraborelli as saying.

The online report says that cops want to interrogate Dr. Conrad Murray, Jackson''s personal doctor, about the singer's drug use.

Dr. Murry was with Jackson when the singer collapsed, and he is the doctor mentioned in the 911 call. (ANI)