World number one Martina Hingis is suing the manufacturer of her sports shoes for £25 million, claiming they have damaged her feet.

Hingis claims, in an action filed in Manhattan Supreme Court, that Sergio Tacchini shoes "caused her chronic injury" and forced her to withdraw from the Wimbledon doubles in June 1999.

Hingis (20), signed a five-year, £3.5 million-plus deal with the Italian company in 1996.

But the deal started to go sour in September 1998, when Hingis was competing in the US Open and "suffered debilitating injury to her feet", the action says.

"She had the injury examined by a Manhattan doctor, who confirmed that the injury was a chronic one and was being caused by the tennis shoes manufactured by Tacchini," the suit alleges.

The injury forced the star to miss tournaments in Germany and Switzerland a month later, while an orthopaedic doctor recommended by Tacchini said the company should "modify" her shoes, the court papers say.

The company did give her new shoes, but the problem remained, says the suit.

"From November 1998 to June 1999, Hingis continued to suffer injury" and was forced to drop out of Wimbledon and get treatment on her feet during nine separate tournaments, the suit claims.

Hingis was dropped by the company in April of 1999, claiming she "repeatedly breached her contractual obligations" by not wearing the clothing she was supposed to.

"She damaged our image and our products because of her behaviour and extremely discrediting statements," Tacchini said in a press release then. "We could not tolerate this attitude any longer."

Hingis's lawyer, Randy Mastro, told the New York Post: "The complaint speaks for itself."

The action describes Tacchini's press release as "false and defamatory." Hingis is seeking £25 million for negligence and breach of contract.