Demi Lovato - Demi Lovato Reveals Secret Half-sister

The Skyscraper hitmaker recently discovered her estranged dad welcomed a daughter over 10 years before marrying the pop star's mother.

The 20 year old, who already has two sisters, Dallas Lovato and child actress Madison de la Garza, announced the shocking news during an appearance on radio show Dana & Jeffrey in the Morning on Tuesday (05Mar13), but she declined to give the name of her new sibling.

She said, "I have an older sister that I've never known my whole life. She's in her 30s. She's my half-sister but I talked to her for the very first time in my life around when I turned 20. I asked her, I said 'Why haven't you ever contacted me?' and she just said, 'Well, because I never wanted you to think that I wanted anything from you... I've just been kinda of waiting to see if you wanted a relationship.'

"I just thought that was so incredible... I have a third sister that I didn't know until this (past) year."