Pop singer Demi Lovato is in a Los Angeles hospital after a suspected drug overdose, US media report.
The Los Angeles Police Department reportedly responded on Tuesday to a medical emergency in the Hollywood Hills, where Lovato lives.
TMZ reports the 25-year-old was found unconscious and treated at the scene with Naloxone, an anti-overdose medicine, after possibly taking heroin.
The Sorry Not Sorry singer was in a stable condition, US media report.
She was alert and breathing at Cedars-Sinai Medical Center, NBC News reports.
Lovato has struggled with substance abuse for years, and appeared to relapse in recent weeks.
Last month she cancelled her show at London’s O2 arena, announcing the news on Twitter hours before the concert was due to begin.
In a single released last month, Sober, she sings: “Mommy, I’m so sorry I’m not sober anymore. And daddy please forgive me for the drinks spilled on the floor.”
The song ends with the lines: “I’m sorry that I’m here again, I promise I’ll get help/It wasn’t my intention, I’m sorry to myself.”
The track release followed Lovato marking six years of sobriety in March this year.
She was due to complete the North American leg of her Tell Me You Love Me world tour with a concert in Atlantic City, New Jersey, on Thursday.
Her fans say the singer’s battles with bipolar disorder, bulimia and addiction – often documented in her music – have helped them with their own struggles.
The BBC contacted Lovato’s representatives on Tuesday, but did not receive an immediate reply.
As reports of her condition spread, there was an outpouring of support on social media from other celebrities and musicians.
Within hours of the report, tens of thousands of people had tweeted the hashtag #PrayforDemi.
According to US health officials, 115 Americans die from an opioid overdose every day with more than 250,000 Americans dying over the past decade.
Raised in Dallas, Texas, Lovato first entered the spotlight on the children’s TV series Barney & Friends.
She appeared alongside the Jonas Brothers in the 2008 Disney Channel movie Camp Rock.
Lovato released her first studio album, Don’t Forget, in 2008.
In a YouTube documentary, Simply Complicated, released last October, Lovato revealed her drug use began when she first tried cocaine at the age of 17.
“I felt out of control the first time I did it,” she said. “My dad was an addict and an alcoholic.
“Guess I always searched for what he found in drugs and alcohol because it fulfilled him and he chose that over a family.”
Lovato went to rehab for the first time in 2010.
“I wasn’t ready to get sober,” she said in the documentary.
“I was sneaking it on planes, sneaking it in bathrooms, sneaking it throughout the night”.
More on the US drug crisis