A Mexican property developer from one of the country's wealthiest families has been arrested after his 11-year-old son died during a boating trip on Sunday 15th September.
Javier Burillo, 57, was held on suspicion of manslaughter and operating a boat under the influence, police in California said.
The boy and his older brother were allegedly thrown overboard by a wave and then struck by the boat.
Mr Burillo posted $1m (£800,000) bail on Monday 16th September, local media reported.
Tiburon Police Chief Michael Cronin said Mr Burillo and his family were on a family trip on Sunday in waters near San Francisco when the boys, 11 and 27, were knocked overboard.
The boys were then allegedly hit by the vessel Mr Burillo was operating. Mr Cronin said there was a "fair possibility that they were swept under" or were hurt when their father turned the boat to rescue them.
The older son had cuts to his leg, but his younger sibling "sustained severe traumatic injuries", a police statement said.
The father took his two sons to the Corinthian Yacht Club, where his younger son was pronounced dead, police said. Mr Burillo contacted police on Sunday night and failed an alcohol breath test, local media reported.