The Russian singer rose to fame as one half of the chart-topping girl group, alongside Lena Katina, but the All the Things She Said singer admits she can no longer hit the high notes.

Now 31, Julia, who performed during the Opening Ceremony of 2014's Sochi Winter Olympics, reveals she underwent surgery during her battle with thyroid cancer - and her voice never came back.

"It was a critical moment for me," she says. "When the surgery was over, I had to open my eyes and start talking. I lost my voice because of the doctors' mistake. I mean they hurt my vocal nerve."

She tells The Mirror the surgery she underwent in Moscow initially left her unable to speak and she is now seeking further treatment in South Korea to restore her voice.

Julia admits she hid her cancer from friends, even during her Olympics reunion with her bandmate Lena, but she insists she is refusing to dwell on the past.

"All the worst is behind me," she smiles. "I never think why or what for."

While she doesn't perform much these days, Julia, who has two children, 11-year-old Viktoria and a son Samir, eight, courted controversy in 2014 when she appeared on a Ukrainian game show and made comments which were considered to be homophobic towards homosexual men.

Despite her own past as one of pop's leading 'lipstick lesbians', she told the show's host she would condemn her son if he announced he was gay, explaining, "I would condemn him because I believe that a real man must be a real man..."