Salerno Prosecutor Giuseppe Borrelli told a news conference of the investigation on Saturday.
The 45-year-old woman, president of Bloomsbury USA, died after being thrown into the water and reportedly hit by the boat’s propellers.
The speed boat collided with a 45-metre sailing ship, the Tortuga, which had around 80 foreign visitors on board celebrating a wedding.
Vaughan was on the chartered speed boat with her husband, who suffered limb injuries in the accident and is in hospital, and her two children.
The prosecutor said that one of the children ended up in the sea too.
The skipper was positive in a toxicology test taken after the crash.
But Borrelli stressed that “no matter what the result of the tests were, it is necessary to verify whether there is a causal link to the collision”.
He added that prosecutors had spoken to over 70 eye witnesses, including Vaughan’s husband.
The 30-year-old skipper suffered fractured ribs and injured his pelvis in the accident, sources said.
He is in a different hospital to the husband.
ANSA
