Naomi Campbell suffered a torn ligament in her leg after she was violently attacked and robbed on a Paris street.The British supermodel was recently sporting a cast on her leg for a mystery injury and it has now been revealed she was set upon by a group of thugs after she tried to hail a cab in the French capital during the incident last month. A source told the New York Post newspaper: ''It was terrifying. Naomi believes the assailant had been watching her, casing her out, and waited for a moment to strike when she was alone. She was attacked in the street as she hailed a cab, and robbed. ''Her leg was injured as she was violently pushed to the ground. She was understandably very upset and shaken up.'' It is not known what the thugs stole from her, but it's believed they were targeting the expensive jewellery she may have been wearing. The 42-year-old beauty's billionaire boyfriend, Vladimir Doronin, immediately flew her by private jet to Vail, Colorado, where she was treated by J. Richard Steadman, one of the top orthopaedic surgeons in the world. Naomi has been using a wheelchair and crutches to get around following the attack, and Vladimir has upped security around her.