Switzerland's Martina Hingis has been threatened with legal action by the Italian sportswear group, Sergio Tacchini, over a long-running shoe dispute.
The Milan-based company said in a statement that recent claims by Hingis and her mother that Tacchini shoes may be behind injuries troubling the 21-year-old Swiss tennis star were false and hurting company interests.
"Groundless remarks ... about the quality of the company products could lead to civil and penal liabilities," said the sportswear group.
Hingis's mother, Melanie Molitor, said recently that the joint injuries suffered by the former world number one may have been caused by the shoes her daughter wore for tennis from the age of 11 until three years ago. Tacchini had a five-year sponsorship deal with Hingis.
Last Monday, Hingis underwent surgery to repair left ankle ligaments and her doctor, Heinz Bühlmann, said she would need 6-8 weeks to recover.
Hingis, who has won five Grand Slam tournaments in her career, filed a $40 million lawsuit against Sergio Tacchini last June, claiming that she had been provided with "defective" shoes "unsuitable for competition", forcing her to withdraw from several tournaments.
Sergio Tacchini said the claims had been made only so Hingis could avoid paying damages for breaching her contract with the company.
swissinfo with agencies