Israeli media on Friday reported that Erez Shimoni, the retired Mossad agent who was killed alongside two other Italian intelligence officers in a boat capsize incident in a lake in northern Italy and the boat owner's wife, was there "as part of an operation against Iranian activity."

Last week, Italian media said a tourist boat on Italy's Lake Maggiore capsized reportedly due to a sudden whirlwind, killing four passengers.

According to the Israeli Channel 12, "Shimoni was working in the area as part of an operation targeting Iranian non-conventional weapons capabilities," adding that the agents were celebrating the mission's accomplishment.

The channel had previously mentioned that the man had only lately retired from Mossad.

On Thursday, Italian police investigating the incident confirmed that 13 of the passengers had ties with Mossad, while eight were either current or former members of the Israeli spying agency.

The Italian newspaper Corriere della Sera had reported that the intelligence agents attended confidential meetings in the Italian region of Lombardy for information exchange and classified documents.

The newspaper also suggested that the agents were allegedly spying on Russian businessmen who were buying an estate in the area circumventing the sanctions that the European Union had imposed against Russia.

Another theory was that the agents were investigating ties between Iranian and Italian firms in the Lombardy industrial zone. 

The Israeli news website Walla also cited Italian reports as saying that 18 survivors were swiftly escorted out of hospitals and hotels "so as not to leave a trace."

The Israeli Channel 12 previously described the boat capsize and the death of Shimoni as a "seemingly mysterious" event.

Read more: Mossad agents on capsized boat met with Italian int. to exchange intel