A Gulfstream jet with blocked credentials has flown into Wellington Airport, according to an online aircraft tracker.

FlightRadar24 showed the jet arriving in the capital on Monday evening.

It is not known why the aircraft is in Wellington, but it follows a weekend of clandestine activity in the country.

JAMES ALLAN/Supplied FBI director James Comey arrives in Queenstown with police and secret service personnel ahead of a top-secret meeting involving the Five Eyes international spy alliance.

On Saturday a jet with the tail number – five small, black digits on the back of the plane – belonging to the Central Intelligence Agency, also known as the CIA, was seen parked at the capital's airport.

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And on Sunday, FBI director James Comey​ flew into Queenstown on a Gulfstream jet ahead of a top-secret meeting said to involve numerous international spy agencies.

JAMES ALLAN FBI director James Comey arrives in Queenstown.

Prime Minister Bill English was staying mum on which Five Eyes' security bosses were visiting Queenstown at the moment, though he did confirm it was indeed them – and that he would be meeting them there later in the week.

He was equally reticent about why the official US plane had flown to Invercargill, other than to say "it was probably a more attractive destination" and that it was unfortunate they didn't have to drive through his hometown of Dipton to get there.

Wellington Airport could not be reached for comment on Monday.