This is according to a former head of the Maritime Section of the UK's Foreign and Commonwealth Office.
Craig Murray told Sputnik that because the boat, the Zaytouna-Oliva, is registered in the Netherlands, it is therefore governed by Dutch law.
The ship, the latest to attempt to break the naval blockade of the Gaza Strip, was boarded by the Israeli Navy Wednesday, October 5, while in international waters.
#BREAKING
— #LetFFlotillaSail (@rayyoosheh) October 5, 2016
Hijacked #Zaytouna #WomenToGaza boat just arrived at #Ashdod port
V @AJABreaking
13 women kdnpd n intl water#SOSWomenFlotilla pic.twitter.com/ZNb49xRlPj
"The jurisdiction of a ship outside the 12 mile territorial limit lies with the flag state," Mr. Murray told Sputnik.
"In this case this is an act of aggression by Israel against a ship from the Netherlands state. Whatever happened on board is governed by Netherlands law. The Dutch authorities have a duty to react to Israeli military seizing people on what was in effect Dutch territory. The role of the Dutch government is going to be very important."
The women traveling on the boat included 1976 Nobel Peace Prize winner Mairead Maguire. As part of the Freedom Flotilla Coalition, a number of boats have sought to break the blockade of Gaza.
The Zaytouna-Oliva is believed to have been taken to a port in Ashdod.
Israeli Prison Service spokesman Assaf Librati, told Palestinian News Agency Ma'an that 11 of the women were being held in the Givon prison in central Israel but that he was not sure of the whereabouts of the other two crew members.
The Israeli Navy said the boat had been redirected in order to prevent a "breach of the lawful maritime blockade" of the Gaza Strip.
However, speaking to Sputnik, Mr. Murray disputed that the blockade of the Palestinian enclave is legal.
"If Israel were in a state of war it would arguably have the authority to enforce a blockade under the San Remo convention. But Israel in general, doesn't accept it's in a state of war," Mr. Murray told Sputnik.
"In any event, even if you were to accept Israel was at war, the San Remo convention does not allow you to blockade food and essential supplies from the civilian population. This particular ship wasn't carrying any cargo at all. So really, there is absolutely no blockade argument for preventing it passing.
"Plainly this was just an act of illegal aggression on the high seas," Mr. Murray added.
Hamas, who control the Gaza Strip, criticized the seizure of the ship as an act of "state terrorism."
