New Zealand Prime Minister John Key has assured the public that any data shared with international intelligence agencies were legal.

According to reports, Mr Key has confirmed that data gathered by the Government Communications Security Bureau (GCSB) may have been used to identify the targets for U.S. attacks using unmanned aircraft.

Mr Key denied supplying information that led to the death of Daryl Jones, a New Zealander, in a military drone strike in Yemen in 2013. He revealed New Zealand has shared data with the Afghanistan's International Security Assistance Force but the prime minister was not sure of the exact information.

Mr Key acknowledged it was possible that it was used to pursue people who were deemed as threats.

According to Greens co-leader Russel Norman, New Zealand's data sharing poses "serious ethical questions" since this could lead to extra-judicial executions. He said the issue is not about whether agencies are acting within the law.

Mr Norman has urged the New Zealand government to shut down the Waihopa facility which has been identified as a crucial part of intelligence activities.

According to Radio NZ, Defence analyst Terence O'Brien said New Zealand's inclusion in the Five Eyes Network should be subject to debate. A senior fellow at the Centre for Strategic Studies at Victoria University, Mr O'Brien said the Five Eyes network is tasked to help pursue war against terrorism. He questioned whether there is a need for New Zealand to be involved in something like that.

Lance Beath, another senior fellow, has a different perspective. He said the sharing of information is part of standard procedure and is only part of the country's contribution to the International Security Assistance Force in Afghanistan.

In Britain, a human rights group has criticised the New Zealand government for its involvement in the drone killings. The group described the killings as "death penalty without trial."

Security researcher Nicky Hager said New Zealand sharing intelligence with the U.S. is pulling the country into wars it has no business in. He told Morning Report that New Zealand was turning its back on its principles by aiding the U.S. in "unjustified attacks" in Afghanistan, Pakistan, and Yemen.

Mr Hager said Mr Key was being "flippant" about New Zealand's role in other countries' wars.