Two Italian intelligence agents and a former Mossad operative have been killed in a freak weather accident at an Italian tourist hotspot.

The retired Israeli security forces officer was among four people who drowned when a small boat capsized due to stormy weather during a birthday party on Lake Maggiore on Sunday night.

Claudio Alonzi, 62, and Dr. Tiziana Barnovi, 53, were identified by Italian media as intelligence agents, while the Israeli government declined to name the former Mossad agent but confirmed he worked for the intelligence agency.

Russian citizen Anya Bozhkova, 50, was believed to be the wife of the captain of the ship also died in the accident.

The rest of the 22 people who were on board managed to swim to shore or were rescued by other boats and five of them were injured in the incident.

Local authorities have said that the boat was capsized by severe weather in the Italian region of Lombardy on Sunday night, which also caused delays at Milan's Malpensa airport.

According to the Guardian, the regional prosecutor’s office has announced it will be conducting an investigation into the circumstances of the event as well as the safety of the boat, believed to be a hired vessel.

Ten former Israeli intelligence agents survived the incident on northern Italy’s Lake Maggiore on Sunday and were rushed back to their home country aboard a military plane.

According to reports in Italian media, 18 of the 20 survivors were either active or former intelligence agents.

On Monday, the Israeli embassy in Rome confirmed that a 50-year-old Israeli had died and that his family had been notified. The embassy was working on bringing his body to Israel for burial.