Four people, including a Mossad agent, died when a small yacht capsized in a lake in northern Italy late last month with new information coming to light suggesting it was more than a freak accident.

The Mossad agent who drowned in Lake Maggiore -- identified with the cover name Erez Shimoni – was one of the 21 Italian and Israeli intelligence agents who were apparently celebrating on the vessel -- named the Gooduria -- before a sudden storm capsized the boat. 

Initially, the Italian media said the agents were having a birthday party, but Israeli media said they were celebrating the success of a mission, which was later revealed as an operation against deals between Iranian and Russian officials to provide drones for President Vladimir Putin’s invasion of Ukraine.

The story is still shrouded in mystery and unanswered questions but during the past few days more and more pieces of the puzzle are coming together.

All 21 passengers -- 13 of whom were Israelis -- on the 52-foot houseboat were currently or formerly tied to Israeli and Italian defense and intelligence work. Two of those who died had worked for the Italian intelligence authority.

The fourth was the Russian wife of the boat's skipper, who was the only other crew except for her husband, Carlo Carminati, the only one under suspicion of negligent homicide, as the vessel had 23 people on board when it was only allowed to carry 15. The captain’s wife, Anna Bozhkova, had a residency permit to live in Italy indefinitely, reportedly to serve as a translator in monitoring the Russian oligarchs’ dealings with Iran.

The passengers who survived swam a short distance – about 150 meters (about 490 ft) -- to reach the shore, where they were promptly rescued. The Israeli agents were flown home on a plane that picked them up in Milan the following day.

One of the main bits of information that was the fact that the Mossad agent was a veteran agent and was operating in the area -- along with the other Israeli agents and Italian intelligence personnel on the yacht -- as part of a mission to target Iranian weapons capabilities, specifically to prevent Tehran from obtaining advanced weapons, according to a report by the Italian newspaper La Repubblica.

The collaboration of Italian and Israeli agents followed reports of Russian oligarchs in the area taking part in transferring Iranian-manufactured UAVs to Moscow.

According to the New York Times, the spies had been scoping the lake for Russian magnates living nearby, while other reports in the Italian press claimed that the group had met "to exchange information and documents." There are also reports that theorized that the Israeli agents were monitoring contacts between Iranian and Italian firms.

Italian daily Corriere della Sera alleged that the Russian oligarchs used their Swiss bank accounts to transfer funds to Iranian companies in order to bypass the sanctions against Moscow and Tehran. The newspaper also highlighted the joint operation conducted by the Mossad and Italian intelligence, saying the operation targeted the proliferation of non-conventional weapons and their potential transfer to a “hostile Middle Eastern country.”

Italian newspaper La Repubblica confirmed that the intelligence operation sought to obstruct the arrival of weapons of mass destruction to Iran as well as preventing the acquisition of "dual-use" items that could serve both civilian and military purposes.

Lake Maggiore or Verbano, the second largest lake in Italy and the largest in southern Switzerland, is a large lake located on the south side of the Swiss Alps -- between Italy's Lombardy region and the Swiss canton of Ticino. Several companies that produce both military and civilian technology use are located in Lombardy, the BBC reported, adding that Switzerland is considered a transit country for those working in intelligence.

An Italian police source played down the intrigue. “Anyone can write what they want to, they could even say the boat was targeted by aliens. But what happened is that there was an accident caused by a weather event... it's not your typical 007 occasion," they said.

However, there are very few ways you can make a story that involves Israel’s Mossad, Italian military officials, Russian oligarchs and Iranian weapons and a picturesque location like Lake Maggiore that would not make a good spy flick.