Lawyers for Canadian star Eugenie Bouchard on Friday accused US tennis officials of destroying video evidence that could shed light on her 2015 fall at the US Open.
A filing in New York by attorneys for Bouchard said the US Tennis Association had "knowingly and wilfully" destroyed security camera footage relevant to the case.
Bouchard withdrew from the US Open two years ago after sustaining a concussion during a locker-room fall.
The 23-year-old later sued the USTA, accusing the body of negligence, asserting that she slipped because the locker room floor had been cleaned with a "slippery, foreign and dangerous substance."
In a further filing related to the case on Friday, Bouchard's lawyers said the USTA had ignored a request to retain camera footage.
"(Bouchard) respectfully requests that the court find that defendants knowingly and wilfully destroyed security camera footage relevant to plaintiff's claims in this case, despite having been notified well in advance to preserve any such evidence," the Bouchard's attorney Benedict Morelli wrote.
The USTA did not immediately respond to a request for comment.
Bouchard exploded onto the women's circuit in 2014, making a memorable run to the final at Wimbledon where she lost to Petra Kvitova.
She also made the semi-finals of the Australian Open and French Open the same year.
However her form tailed off in 2015 and she failed to go further than the third round in any of the four Grand Slam events in 2016. Bouchard is currently ranked 56th in the world.