Weiland was found late last night in his bed not breathing. The report on the emergency call stated he died of cardiac arrest. Today there is new information. I may be misinterpreting the wording of the Rolling Stone report, but after re-reading it a few times, it seems to me that a small amount of cocaine was found in the room of the bus where Scott's body was discovered:
A small quantity of cocaine was present in the tour bus bedroom where Scott Weiland was found dead, Bloomington, Minnesota police reported Friday. Detectives discovered the controlled substance after searching the tour bus where the former Stone Temple Pilots and Velvet Revolver singer, who had had a long complicated relationship with substance abuse, was found.
In addition, police also found cocaine in the bunk of bassist Tommy Black and arrested him on charges of possession of a controlled substance.
This corroborates with a report from TMZ that stated friends being worried that Weiland was falling into a crack-cocaine habit, which his wife denied. We will know soon enough, when the autopsy report comes in a few weeks.