Demi Lovato arrives at the American Music Awards in Los Angeles. Picture: AP

Demi Lovato reportedly fell out with her sober coach at the beginning of the year and fired him just three weeks before her suspected overdose.

The 25-year-old singer is currently recuperating in hospital after she was found unconscious at her home in Los Angeles after taking a mystery substance but, although she's managed to keep her break in sobriety under wraps until now, it's believed she began to slip off the straight and narrow at the beginning of the year when she started rowing with her counsellor Mike Bayer. 

A source told The Sun Online: "She and Mike started having arguments back in March.

"He felt like she was always making excuses for herself, her bad behaviour and not telling him the truth about what she was up to. He called her out on her s***. which she did not appreciate.

"She fired him a few weeks ago - they had a big argument and then they unfollowed each other on social media. It has been very ugly and messy as this guy was like 'her rock' that she leaned on after she and Wilmer [ ex-boyfriend actor Wilmer Valderrama] broke up.

"She has been alienating people all around her, but she is very much well liked in Hollywood - people just want her to get well and get help."

It's believed the 'Sorry Not Sorry' hitmaker - who has been battling with alcohol and drug abuse for years - hired Mike after she first sought help in rehab for her addictions back in 2010. 

The brunette beauty managed to remain sober for six years before hinting recently that she had fallen off the bandwagon when she released her single 'Sober', in which she tells her friends, family and fans that she's hit the bottle once again and she's "sorry" for letting them down.

However, the extent of her issues weren't fully understood until Demi - who has battled with cocaine addiction in the past - was rushed to hospital this week following a suspected overdose. 

Her relatives - who are currently at her bedside - are now desperate to get her back into rehab.