Demi Lovato has released a new single in which she suggests she suffered a setback in her recovery from addiction.

The singer, 25, refers to a relapse on her latest track, titled Sober.

The release comes after she celebrated six years of sobriety in March.

In Sober, she sings: “To the ones who never left me, we’ve been down the road before. I’m so sorry. I’m not sober anymore.”

She does not say whether the lyric refers to now or in the past.

American star Lovato has been open with fans on her struggles with mental illness and substance abuse.

She has discussed her use of cocaine and addiction to alcohol as well as having an eating disorder.

Earlier this month she was forced to cancel two UK shows due to illness.

Lovato called off concerts in London and Birmingham after suffering from swollen vocal cords.