Irish activists yesterday accused Israel of sabotaging a ship due to join an aid flotilla to challenge an Israeli blockade of the Gaza Strip, forcing the vessel to withdraw.

The Irish Ship to Gaza (ISG) campaign said the ship’s propeller shaft had been cut or had a piece gouged out of it, which could have caused it to break and pierce the hull of the vessel once it set sail.

The group said the damage was identical to that suffered by a Swedish-owned ship that had also been due to join the flotilla.

The Irish ship, the Saoirse, had been “sabotaged in a dangerous manner” in the Turkish port of Gocek where it has berthed for the past few weeks, ISG said.

The Irish government said it would take a “very serious view” if sabotage was proved, but said it was up to the Turkish authorities to carry out an investigation.

The Irish group insisted Israel was to blame. “Israel has questions to answer and must be viewed as the chief suspect in this professional and very calculating act of sabotage,” it said in a statement.

But Israel dismissed the allegations as “paranoid”, saying the flotilla organisers did not have “a shred of evidence” to support their claims.

The Irish group said it would take so long to repair the damage that the Saoirse would not be able to join what is known as the Freedom Flotilla 2. The Irish activists had been re-deployed to other ships. Organisers insisted the flotilla would still set sail despite the alleged sabotage and bureaucratic hitches, but not before this weekend at the earliest.

Israel has repeatedly said it is determined to stop the flotilla.

Israeli troops ended a similar attempt by a multi-national flotilla to reach Gaza in May last year when they stormed the lead vessel, killing nine Turkish activists and sparking a diplomatic storm.

Foreign Minister Avigdor Lieberman yesterday urged the organisers not to create “new friction” in the region.