An Irishman who was detained in Israel after Israeli commandos shot dead nine people on a flotilla of ships heading for Gaza has told the United Nations that he received a "serious threat" from an Israeli official who is close to the Israeli Prime Minister.

Fiachra O'Luain from Carndonagh in County Donegal was second mate on the Challenger 1 and told how he watched in horror as the Israeli forces descended onto the Mavi Marmara and opened fire.

The 28-year-old local man said that in the light of the threat he had yet to decide whether he would return on the next aid convoy in October.

O'Luain submitted his statement of evidence to the United Nations Secretary General's Panel Of Inquiry this week. In his statement, he revealed how he had alerted Senator John Kerry’s office in the United States and the Irish Department for Foreign Affairs to the "serious threat" he had received in an email from an official close to Binyamin Netanyahu.

In his evidence O'Luain said: "The official wrote: ‘Details have been sent to the Foreign Ministry. May you and your boat sink to the depths of the sea, may you know the punishment meted out to the enemies of God’s Chosen People.' Knowing how close this man was to the Israeli Prime Minister, I realized how serious this threat was."