A former tennis star and rumoured ex-lover of Nick Kyrgios was caught driving with cocaine in her system.

Glamorous party girl Monique Belovukovic, 21, was driving her black Mercedes down Sydney's Oxford Street when she was pulled over by highway patrol officers.

Court documents revealed that she tested positive for cocaine at around 2pm on November 11 last year, the Daily Telegraph reported.

Monique Belovukovic, the 21-year-old rumoured ex-lover of Nick Kyrgios (pictured together), was busted driving her Mercedes after taking cocaine in Sydney last November

Ms Belovukovic (pictured) plead guilty to driving with an illicit drug present in her system

Ms Belovukovic was excused from appearing at the Downing Centre Local Court on Thursday, where her lawyer, Elias Matouk, entered a guilty plea on her behalf.

The former tennis star, who now lives in Randwick, plead guilty to driving her G-class wagon with an illicit drug present in her bloodstream or oral fluids.

She is due return to court to be sentenced on April 27.

Ms Belovukovic shot to fame when she was photographed partying with Kyrgios in 2017.

The pair enjoyed a cosy night out in London just hours after Kyrgios pulled out of his first-round match in Wimbledon with a hip injury.

Ms Belovukovic was a student at Reddam House in Sydney's eastern suburbs and learned to play tennis at the famed White City Tennis Club.

A promising junior player, the blonde glamour won a number of tournaments locally while also travelling to Serbia, France, Italy and Fiji to take on the world's best.

At the age of 14 she moved to France to train at the Mouratoglou Tennis Academy, which was founded by Serena Williams' current coach Patrick Mouratoglou.

But while she had mixed results at junior level, her transition to the world senior tour proved a challenge, as she recorded no career wins and career earnings of $350.

She eventually quit her tennis career and expressed interest in becoming an actor and model.