"X Factor" judge Tulisa Contostavlos apologized last night to fans as she admitted it was her in a sex tape touted online.
The N-Dubz singer, 23, claimed the tape showed an "intimate moment" with ex Justin Edwards.
And she said that the DJ — called MC Ultra — had "betrayed" her by posting the X-rated video online.
She said: "I am devastated, heartbroken.
"When you share an intimate moment with someone that you love and trust you never imagine for one minute that footage may at any point be shared with the rest of the UK."
The film, from a high-quality camera phone, shows Tulisa performing a sex act for over six minutes.
An internet firm charged viewers to download it on Monday but the site was suspended several hours later.