The model daughter of Formula One mogul Bernie Ecclestone told the Sun newspaper: "I have spoken to Omar and he has admitted that it's true. It's over now."
Tamara is now being comforted by her father and her mother Slavica. She has also been in phone contact with her 22-year-old sister Petra, who has been offering words of advice.
The 28-year-old attended The Dark Knight Rises premiere in London on Wednesday with Omar, though they did not pose together on the red carpet.
There were clues on her Twitter account on Thursday that things were not well, when she posted: "People never fail to disappoint me but I really hope what comes around goes around."
In the past, Tamara had spoken of marrying 38-year-old Omar, a businesman who's family are orginally from Syria.
She said: "Deep down you know when someone loves you for who you are and not what you have.
"I think I’m a good judge of character. Omar and I definitely want to get married. I think in the next few years hopefully we will tie the knot."
The couple were even set to move into a 55-room, £45 million Kensington mansion that they spent a further £18 million renovating.