Osaka silent over ex-coach lawsuit as Miami Open begins

World No.1 Naomi Osaka has arrived in Miami Open but refused to comment on a dispute with one of her former coaches who is suing her for 20 percent of her career earnings.

Christopher Jean, who helped the Japanese two-time Grand Slam champion when she was a junior, wants at least 2 million of the 10 million U.S. dollars of her earnings to date.

Jean insists Osaka's father, Leonard Francois, had signed a contract when he was coaching the 21-year-old and her sister Mari in 2011.

Osaka said she was "not allowed to say anything" about reports of the lawsuit, "I am unable to make a comment."

Osaka's attorney Alex Spiro described the lawsuit as a "false claim" that has no merit.

Naomi Osaka of Japan plays a forehand during BNP Paribas Open in Indian Wells, U.S., March 12, 2019. /VCG Photo 

Osaka, who has enjoyed a meteoric rise and won the last two grand slams to reach top ranking in the world, has career earnings of 10.8 million U.S. dollars and has made millions more in endorsements.

The 21-year-old U.S.-based Japanese player last month just , who guided her to the Australian and U.S. Open titles.

That split, however, appeared amicable with both Osaka and Bajin wishing each other the best for the future.

(With input from Reuters and AFP)