Parliamentary Speaker Trevor Mallard says his bags were packed to represent New Zealand at a global holocaust memorial event in Israel, but organisers turned him down citing security issues.
The Government is facing questions about New Zealand's absence from the Fifth World Holocaust Forum, marking the 75th anniversary of the liberation of Auschwitz-Birkenau and international Holocaust Remembrance Day.
The list of representatives and speakers from 46 countries attending includes US Vice President Mike Pence, Russian president Vladimir Putin, Prince Charles and France's Emmanuel Macron.
Australia is sending its Governor-General, David Hurley, but New Zealand will have no representatives at the event.
National Party foreign affairs spokesman Gerry Brownlee says New Zealand will be one of the only developed nations to not send someone and has called the absence disgraceful and embarrassing.
However, Foreign Affairs Minister Winston Peters say the forum's organisers had requested a Head of State-level attendee but that Governor-General Patsy Reddy was unable to attend.
"We asked organisers if the Speaker or New Zealand's Ambassador to Israel could attend in her place, however this was unfortunately not possible," Peters said.
Speaker Trevor Mallard has told the Herald his bags were packed on Tuesday night to fly out to Israel.
"I got the message to unpack. Apparently there was something to do with security," he said.
"You can't go to commemorations unless you've got the total support and backing of the people who are hosting you."
Peters on Thursday told Radio NZ it was unclear why Mallard's arrangements were an issue.
"We still don't understand why they were unable to provide security, given it's Israel here, he said.
"But that was their position and that's what we accepted."
Peters also said Israel appeared to have misunderstood New Zealand's constitution, suggesting the Governor-General was not an option.
The Governor-Generals of both Canada and Australia, who have similar constitutional arrangements, are attending the forum. New Zealand's Governor-General and Speaker both frequently represent New Zealand at such events.
Dame Patsy has instead sent a written letter to the forum, discussing her visit to Yad Vashem, Israel's official memorial, in 2017 and her sadness over New Zealand's rejection of some Jewish refugees in the 1930s.
"It is only through a deep understanding of the lessons of history that we can ensure atrocities such as the Holocaust never happen again," she wrote.
"May your conference reinforce the message of diversity and inclusion to which we in New Zealand are firmly committed."
Israel's ambassador to New Zealand, Itzhak Gerberg, described the message as touching and inspiring.
Peters said New Zealand's Ambassador to Poland would also be at a commemoration event at Auschwitz.
Prime Minister Jacinda Ardern is speaking at a Holocaust Remembrance Day event in Auckland next week.
Peters has said the previous government had not sent anyone to the forum in 2010 and 2015 either.