Selena Gomez likened longtime pal Demi Lovato to a sister, revealing they have fallen out several times during their friendship.

Lovato has credited Gomez with helping her through her lowest ebb when she was in rehab trying to beat severe depression and addiction issues.

Gomez has now revealed that they have fought like siblings since they became close aged seven on U.S. kids show Barney and Friends, but have come out stronger than ever.

The star tells U.S. radio station Kiss 108, "I think what people forget is that she's actually been there for me, too. I've known her since... we were best friends since we were seven.

"We had a time where we did grow apart, but there's not a single person on this planet that knows me like she does. She goes into my darkest place, and she goes into my lightest most incredible memories. There's nothing like her and there's nothing like us, so I will always cherish her...she's like my sister. I'm very, very proud of her."