Pop star Demi Lovato has been taken to a Los Angeles hospital on Tuesday due to a possible heroin overdose, according to US celebrity website TMZ.

Lovato, 25, who has spoken openly about cocaine and alcohol abuse in the past, released a song last month called Sober, saying she had relapsed after six years of sobriety.

Representatives for Lovato did not immediately respond to a request for comment.

Los Angeles police said they had responded to a medical emergency call on Tuesday involving a woman on the Hollywood Hills street where Lovato reportedly has a home, but declined to name the person.

TMZ, quoting law enforcement sources, said Lovato was rushed to a Los Angeles hospital from her home with what they said appeared to be a heroin overdose. Her condition was not immediately known.

Lovato shot to fame on Disney Channel shows Camp Rock and Sonny with a Chance 10 years ago, and went on to forge a pop career with hits like Skyscraper and Sorry Not Sorry. – Reuters