Nicole Scherzinger. (AFP PHOTO/ MAX NASH)

Pop star Nicole Scherzinger has opened up about her battles with eating disorders and self-harming in a new TV expose.

The former Pussycat Dolls star has revealed she suffered from bulimia at the beginning of her career and became so fixed on what she put into her body it became an addiction.

In her upcoming VH1 Behind the Music special, which will debut in the U.S. on Sunday, the Don't Cha singer explains, "My bulimia was my addiction, hurting myself was my addiction. I never did drugs but kinda doing things to myself was my addiction."

Fighting back tears, Scherzinger admits she has never spoken about her "embarrassing" past struggles because she didn't want to come across as a victim of any kind.

She says, "I've never spoke about it. It's embarrassing... I did it every day for, like, years... I hated myself. I really was so disgusted with myself... I felt so alone; I was in a group and I never felt so alone in my life."

The singer admits her abuse issues peaked in 2003 as she prepared to hit the road with the Pussycat Dolls for the first time: "I got my outfit and it was a bra and some underwear and some garters, and I was like, I can't do this!"

And she reveals she constantly had to hide the scars, cuts and blisters on her hands and wrists, which were the results of what she did to herself when she was alone in hotel rooms: "I tried to hide those but I think the girls (bandmates) could tell."

Scherzinger's bandmate Ashley Roberts admits she knew her pal was struggling with self-harming issues: "We all knew. I saw the scars on her fingers... When you stick your finger down your throat, acid stuff comes up and it scars your fingers."

Scherzinger insists she has conquered her abusive behaviour in recent years.