ROME - Three sportsmen trying to set a new speedboat record were killed when their vessel crashed into a breakwater offshore the lagoon city of Venice and flipped over, firefighters said Wednesday.

A fourth person, the sole survivor of the Tuesday crash, was badly injured, according to firefighters involved in the rescue and retrieval of bodies.

Italian speedboat race officials said the boat was being used in an attempt to set a speed record for the route from Monte Carlo, a Mediterranean port in Monaco, to Venice.

They said the boat began the undertaking Monday morning and rules for setting a record allowed one fuel stop.

Italian state radio said the speedboat was capable of speeds up to 130 kilometres per hour (80 mph).

Earlier Wednesday, authorities said that an Italian and two Britons died in the crash. But later, the Italian coast guard said two of the people who died were Italian and the third was a foreigner. Italian news reports said the other victim was possibly Dutch, and not British.

None of the dead were publicly named pending notification of next-of-kin.

The hospitalized survivor is Italian.

The coast guard was investigating the crash. Authorities said possible factors include the boat's speed and the crew's exhaustion; the speedboat had apparently travelled non-stop for about 20 hours.