The skipper of a rented motorboat involved in a crash off the Amalfi coast that killed a US publishing executive is being investigated for suspected manslaughter, a prosecutor in southern Italy said.

Salerno chief prosecutor Giuseppe Borrelli told a news conference in the port city that the skipper, an Italian who has not been publicly identified, is also being investigated on suspicion of causing a shipwreck.

No charges have so far been filed against him, and the investigation is still ongoing.

Adrienne Vaughan, 45, was killed and her husband and the skipper of the rented motorboat were injured in the accident on Thursday afternoon off a stretch of coastline popular with tourists.

The motorboat slammed into a chartered yacht, where some 70 guests aboard were enjoying a wedding reception.

Blood samples were taken from the skipper to determine alcohol and drug levels.

But Mr Borrelli indicated that for now the results were inconclusive.

“The results are being evaluated by a consultant of the prosecutor’s office since the data per se aren’t necessarily significant,” Mr Borrelli.

He added that more evaluation was needed to determine “the incidence of the levels on the ability of the subject” to pilot the boat.

On Friday, Italian news reports said that the blood toxicology tests had found traces of cocaine.

Investigators have questioned the skipper, who remains in hospital with what Italian media said are pelvis and rib fractures.

The victim’s husband, Mike White, is being treated at another hospital for a shoulder injury, according to reports.

Authorities have spoken to him and plan to do so again, Mr Borrelli said.

The couple’s two young children were uninjured.

Ms Vaughan was thrown into the water by the impact and was repeatedly struck by the motorboat’s propeller, according to Italian news reports.

Two doctors who were among the passengers on the yacht dived into the sea to help Ms Vaughan, while a nearby vessel brought her to shore.

Mr Borrelli said the woman died before a medical helicopter and local ambulance could take her to hospital.

The yacht’s captain has told Italian media that the motorboat was speeding when it smashed into the stationary yacht’s bow.

The prosecutor said investigators also questioned the captain of the yacht as well as some 70 passengers including American and other foreign tourists.

The motorboat had set sail from the town of Amalfi, Mr Borrelli said.

According to Italian media, the family was heading to Positano, another popular coastal town, when the crash happened.

Ms Vaughan was president of Bloomsbury Publishing’s US branch, which counts writers ranging from bestselling novelists Sarah J Maas and Susanna Clarke to historian Mark Kurlansky among its roster of authors.

A Bloomsbury book, Chasing Me To My Grave: An Artist’s Memoir Of The Jim Crow South, by the late Winfred Rembert (as told to Erin I Kelly), won the Pulitzer Prize for biography in 2022.