Demi Lovato supported by ex Wilmer Valderrama

Demi Lovato is reportedly relying heavily on support from ex Wilmer Valderrama to stay sober.

The 26-year-old singer recently left rehab after a 90-day stint, which followed her hospitalisation from an overdose in July. She is spending three days a week at a sober house, which has counselling staff on hand, as well as people who she can share experiences with.

But it's believed to be her regular chats with the 38-year-old actor that are helping her the most, with a source insisting they are just good friends.

An insider told TMZ, "She and Wilmer still communicate regularly. Valderrama was a crutch for Demi through her hospitalisation, and visited her in rehab, too. The two talk several times a week, and meet up as well ... but it's nothing romantic, simply a supportive friendship."

The Sorry Not Sorry hitmaker has been attending regular Alcoholics Anonymous meetings, and earlier this week, she was pictured catching up with Henry Levy, who she met on a previous stint in rehab, and pals think the clothing designer is a "perfect sober friend" for her.

The Sober singer has vowed to "dedicate herself" to a life of sobriety, following several years of struggling with addiction, and is thought to be distancing herself from her old group of friends, with the exception of Wilmer.

A source says, "She is avoiding those in her social circle that supported her precarious lifestyle. Demi deserves a partner who will help her continue to live a clean life, and her family and friends feel she is choosing more appropriate friends."