A report concludes that an unidentified third vehicle illegally cut off the tennis star as she tried to cross a busy six-lane road near her home – setting off the chain of events that ended with a sedan slamming into the passenger side of her SUV.

Jerome Barson, a 78-year-old passenger in the sedan, died 13 days after the crash on 9 June. Williams was not hurt.

The police report said that his wife Linda, who was driving, should have checked to make sure that Williams had left the intersection before proceeding – even though she had the green light.

Mr Barson’s estate has filed a wrongful death lawsuit against Williams, seeking unspecified damages.

In a statement, his family’s lawyer said the police report’s conclusions were wrong.

“Ms Williams clearly violated our client’s right of way because our client had a green light, as indicated in each and every police report issued in this case to date,” Michael Steinger said.

Williams, the older sister of tennis star Serena Williams, has won seven Grand Slam titles, including five at her Wimbledon.

Weeks after the crash, Williams competed at Wimbledon, losing in the finals on 15 July to Garbine Muguruza.

The 37-year-old broke down in tears when asked at a tournament news conference about the crash and Mr Barson’s death.