A pro-Palestinian organisation in New Zealand says it always intended to smear blood and paint on an Israeli memorial.
Catholic priest Father Gerard Burns smeared a mixture of red water-soluble paint and a drop of his own blood on the memorial following a protest in Wellington on Tuesday against the Israeli offensive in Gaza.
The memorial was to former Israeli prime minister Yitzhak Rabin.
Medical staff in Gaza say more than 850 Palestinians have been killed since Israel launched an offenisve on 27 December. Thirteen Israelis have also died.
Wellington's Catholic Archbishop said Father Burns was not representing the church, and it is unclear whether he will face any criminal charges.
However, Omar Khamoun, from the Wellington Palestine Group, said it was always their intention to smear the mixture over the monument.
Mr Kahmoun said Father Burns had enough courage to do it on the group's behalf, and it is only right for the group to claim responsibility.
Meanwhile, the Catholic Church is trying to find the writer of a hoax letter published in a newspaper under the name of the Bishop of Auckland which criticised Father Burns.
A spokesperson for the church in Auckland, Lyndsay Freer, said Bishop Patrick Dunn was surprised to read the letter in the newspaper on Friday, as he did not write it and had no knowledge of it.
"He wouldn't have made any comments on the matter because it concerned the priest of another diocese, and the Archbishop of Wellington had already made a statement about it.
"So Bishop Dunn was amazed and very disturbed to think that somebody had sent a letter in his name."
Ms Freer said the church is confident it can track down the source of the emailed letter.
