Demi Lovato couldn't go an hour without using cocaine before she went to rehab.

The 'Neon Lights' singer has opened up about her drug issues for the very first time in an emotional interview with 'Access Hollywood Live', admitting she even used to ''smuggle'' the class-A drug through airport security so she could get her fix on long-haul flights.

A tearful Demi confessed: ''I've really never talked about this stuff before... I don't know if I should be sharing this. With my drug use I could hide it to where I would sneak drugs. I couldn't go without 30 minutes to an hour without cocaine and I would bring it on airplanes.

''I would smuggle it basically and just wait until everyone in first class would go to sleep and I would do it right there. I'd sneak to the bathroom and I'd do it. That's how difficult it got and that was even with somebody [with me], I had a sober companion, somebody who was watching me 24/7 and living with me [and] I was able to hide it from them as well.''

The 21-year-old Disney starlet - who began her career at the tender age of six alongside Selena Gomez on 'Barney & Friends' - checked into rehab in October 2010 for an eating disorder, self-harm and ''addiction issues'', and while she had previously admitted to trying cocaine, she had never discussed the extent of her problems.

The 'X Factor' USA judge also said she used to hide vodka in Sprite bottles and only decided to seek help when it finally hit her she could die.

The brave star said: ''It got really difficult [and] I would throw up and it would just be blood and it was something that I realised if I don't stop this, I am going to die.''