Toxicology tests are to be carried out on Ms Waters' body
A woman who has died in North Yorkshire had recently taken the legal drug mephedrone, police have been told.
Lois Waters, 24, was found at a friend's house in Norton, near Malton, at 0900 GMT on Monday.
The woman's family and friends said she had taken mephedrone "freely" in the 48 hours before her death. She may have also taken other substances.
Miss Waters' mother Alison paid tribute to her daughter saying she was a "really lovely girl".
Deborah Cook, a friend of the family and the landlady of the Union Inn in Norton, described Miss Waters' death as "very sad".
Police said post-mortem and toxicology tests will be carried out in the next two days.
Those tests will determine whether mephedrone, which is sold legally on the internet as "plant food", contributed to the woman's death.
The death follows those of Louis Wainwright, 18, and Nicholas Smith, 19, who died in Scunthorpe last week after taking a mixture of mephedrone, the heroin substitute methadone and alcohol.
Speaking about the Norton woman's death, Det Ch Insp Nigel Costello, of North Yorkshire Police, said: "We can't link it definitely to mephedrone.
"We'll certainly be able to have a better answer of that when a post-mortem and toxicology tests have been conducted later, in the next 48 hours.
"We do know in the 48 hours up to her death she freely used mephedrone and it may have been a cause of her death."
Det Ch Insp Nigel Costello: "It's not meant for human consumption"
Mr Costello said evidence suggested the woman may have also taken other substances.
He said the woman's family were "devastated" and "very cut up" by her death.
The detective warned people about the "devastating consequences" of taking the drug.
He said: "I don't think people should be under the misconception that it's only readily available in big cities. It isn't - it's available in small market towns also.
"It's not a controlled substance, and people are classing it as a legal high.
"We're not seeking to media scare by any means, but people should know the devastating consequences that exist."
The government's chief drugs adviser, Les Iversen, has indicated that his panel will recommend mephedrone be made illegal.
Professor Iversen said he expected a recommendation to be made to the Home Secretary next Monday when the Advisory Council on the Misuse of Drugs meets to consider the issue.