The 15-year-old daughter of Olympic sprinter Tyson Gay has been shot dead in Kentucky, the athlete's agent said.

Trinity Gay was shot during an exchange of gunfire in a restaurant car park, Lexington Police said.

The teenager was taken to hospital, where she was pronounced dead.

Witnesses said the shots were fired by people in two vehicles - a grey Dodge Charger and a dark-coloured sports car with tinted windows.

Police said the Dodge Charger was located and two "possible persons of interest" were detained for questioning. Officers are still looking for the other vehicle involved.

Gay, 34, has competed in the last three summer Olympics. He was part of the US team that won silver in the 4x100 metre relay at London 2012, but he was stripped of his medal after testing positive for steroids a year later.