NZ spy agency head apologises for blunder

The head of the New Zealand spy agency GCSB has apologised to Prime Minister John Key for the organisation's latest blunder.

It made a mistake in its annual report and under-stated the number of access authorisations and interception warrants it used last year.

That has led opposition parties to renew their demands for an independent inquiry into the country's intelligence agencies.

Mr Key is the minister responsible for the GCSB and his office issued a statement saying he was unhappy about the error.

"He has received a letter expressing regret from GCSB director Ian Fletcher," the statement said.

"The prime minister has been advised that the error stems from the GCSB mistakenly counting the number of operations, rather than the number of warrants on issue."

Green Party co-leader Russel Norman described it as "a serious mistake" which raised questions about the GCSB's ability to do its job.

"This mistake is not a small technical issue. It cuts to the heart of their accountability to the government and the New Zealand public," he said on Thursday.

Labour leader David Cunliffe said Mr Key should hang his head in shame.

"It's mind-boggling the GCSB couldn't get the number of warrants it's issued correct in its annual report."

They both want an independent, wide-ranging inquiry into the GCSB and fellow intelligence organisation SIS.

GCSB said in its annual report seven interception warrants were in force in the 2012/13 year and four were issued.

That's been corrected to 11 in force and five issued.

The number of access authorisations was reported as 14 in force and nine issued.

That's been corrected to 26 in force and 11 issued.