The mysterious "senior officials" coming to Queenstown for a conference this weekend are the heads of agencies involved in the Five Eyes spy network, according to an unconfirmed report.
NZME says it believes they include FBI director James Comey and CIA director Mike Pompeo.
There's been speculation for the last two days about the identity of the visitor or visitors, since it was reported police were mounting an extensive security operation in the Queenstown area.
Former US President Barack Obama was the favourite pick, but that was shot down when authorities said no former or current head of state was coming.
Prime Minister Bill English's office said on Wednesday the government was hosting a conference which would be attended by "a number of senior officials" from overseas.
New Zealand's GCSB is part of the Five Eyes surveillance network which involves the US, Australia, Canada and the UK.
A spokeswoman for Mr English declined to comment on the NZME report.