WELLINGTON, April 21 -- Leaders of New Zealand's main China friendship organization expressed dismay Tuesday at reports that New Zealand and U.S. spy agencies planned to jointly hack into Chinese diplomatic communications in Auckland.

Senior members of the New Zealand China Friendship Society ( NZCFS) attacked Prime Minister John Key's attempt to downplay the alleged plan, which was revealed in documents from U.S. National Security Agency (NSA) whistleblower Edward Snowden.

"If there is any truth in this, I would hope that the New Zealand government would have the courage and decency to apologize and commit to not continuing with these actions," NZCFS national president Dave Bromwich told Xinhua.

The NZCFS had been working hard for 60 years to establish a sincere relationship with China and the allegations undervalued that work.

"I would have to say that, assuming these allegations are true, it shocks me and disappoints me," Bromwich said in a phone interview.

"I really query why they think they can get away with it. I don 't think it's the sort of thing we as a country should be involved in," he said.

"We should value our neutrality. This is not a friendly action. "

NZCFS national vice president of the northern region George Andrews said he and northern region members had been frequent and welcome guests at functions in the Chinese Consulate and visa office in Auckland.

"We would never have dreamed that the contacts between the consulate and the visa office would have been invaded in this way, " Andrews told Xinhua in a phone interview.

"It seems to me an affront to the consulate and the relationship between us," he said.

Andrews said he was disappointed at the argument that such spying was "routine these days" and he dismissed Key's claim that the Snowden documents were stolen and unconfirmed.

"Saying they are not confirmed is about the lamest response imaginable it just reflects the hollowness of the position they 're trying to defend," said Andrews.

The NZCFS was formed in 1952 by followers of Rewi Alley, who helped in China's war against Japanese aggression, and maintained contacts between the two countries until diplomatic ties were established in 1972.

The Herald on Sunday newspaper reported that the plan to tap data flowing between the Chinese Consulate and its visa office in Auckland was run by New Zealand's Government Communications Security Bureau (GCSB) and the NSA.

An April 2013 document said the plan had verbal approval, said the report.

But it was unknown if the plan went ahead because, as sign-off was being sought, Snowden walked out of his job with a mass of top secret documents.

The Chinese embassy in New Zealand issued a statement Sunday, saying China was concerned about the report and attached great importance to the cyber security issue.

"We will firmly safeguard our security interests and continue to guarantee our cyber and information security with concrete measures," said the statement.

New Zealand Prime Minister John Key on Monday said his country had a very open relationship with China and he would welcome any discussion about the reported spying on Chinese consulate in Auckland with Chinese officials.

Asked if plans were underway to spy on Chinese communication, Key said in a television interview that "I'm not going to go into those details."