Josie Harris, the mother to three of boxing superstar Floyd Mayweather's children, has been found dead in her car in California.
The 40-year-old was found unresponsive on her driveway, a spokeswoman for the coroner told the BBC.
No information has been released regarding the cause of death.
Harris dated the boxer between 1995 and 2010. He was convicted of her misdemeanour battery in 2010 and later served two months in jail.
She was found outside her home in Valencia, Los Angeles County, on Tuesday night.
US media say that police do not suspect foul play, although this has yet to be officially confirmed.
Harris had reportedly been in the process of suing Mayweather over accusations he made in an interview when asked about the case.
In a 2014 interview, Harris said she preferred it when Mayweather would not collect their children personally from the house.
"For some reason I still get anxiety when I know that he is on his way. I have no idea why, but I get really overwhelmed," she said.
Mayweather, 43, has an unbeaten record in 50 professional fights and at times in his career was listed by Forbes as the highest paid athlete in the world.