Nada Kiswanson, a legal researcher for the Palestinian rights group Al-Haq, believes she is being intimidated in response to her work on behalf of Palestinians at the International Criminal Court (ICC) in The Hague.
She has been cooperating with an ICC probe into possible crimes Israel may have committed in Gaza during the conflict there in 2014.
"It's very clear that the reason I'm being threatened is because of the work that I do in Europe and particularly at the International Criminal Court," she said.
Since the beginning of 2015, the ICC has been carrying out a preliminary review of possible crimes committed by both Israelis and Palestinians in the Gaza conflict in which more than 2,000 Palestinians were killed.
Israel, which rejects the authority of the ICC, said 67 of its soldiers died along with six Israeli civilians.
Kiswanson said the threats began earlier this year and have continued on a regular basis.
"My channels of communication have been totally compromised," Kiswanson said, adding that she had received death threats by e-mail, via family members and in the form of flower deliveries to her home with accompanying messages.
Not even the purchase of an anonymous pre-paid mobile phone number could stop the harassment. She received a threat on it one day later. She said the messages had been sent in Dutch, English and "broken Arabic."
Israeli Foreign Ministry spokesman Emmanuel Nahshon rejected the claims, saying: "We do not react to such preposterous allegations."
But Dutch officials are taking the threats seriously. Prosecutors in The Hague are investigating, and providing Kiswanson with protection, but gave no further details.
"We are taking this very seriously," prosecutors said, adding that their probe includes international requests for assistance.
Kiswanson, a Jordanian-Swedish dual citizen, has also received threats through her family members' phones, including a relative in Sweden who was called and told that Kiswanson would be "eliminated."
Amnesty International temporarily closed its office in The Hague for security purposes after an employee's personal e-mail was hacked and used to send Kiswanson a death threat.
Cases investigated by the war crimes court are always very contentious, but never before have rights workers been threatened in the Netherlands.
The ICC has only a handful of prosecutors and investigators, which means they are very dependent on the work of human rights organizations and volunteers to provide preliminary background material on the war crimes it investigates around the world. However, actual investigations are carried out by the court's prosecution staff.
bik/msh (AP, Reuters)