Interest is high for an upcoming Dunbar Sloane auction, with movie-maker Peter Jackson tipped to be interested in two rare biplanes going under the hammer.

Also on offer is a piece of the infamous flagstaff Hone Heke repeatedly chopped down, kicking off the first of the land wars.

The two biplanes on offer include a 1944 Tiger Moth and the last remaining 1929 Simmonds Spartan in the world.

Peter Jackson is an avid World War I-era plane collector.

Dunbar Sloane confirmed Jackson's buyers had been alerted to the upcoming sale and had shown initial interest.

"But we won't know if he is going to put in a bid until the day. Buyers don't usually let us know they are definitely bidding before the day."

Only 49 Simmond Spartans were ever produced before designer Oliver Simmonds went on to assist in the design of the Supermarine Spitfire, which was used by the Allies in World War II.

The Simmond Spartan is expected to fetch between $250,000-$350,000 and the Tiger Moth $160,000-$180,000.

The flagstaff piece is believed to be just one of three that were kept after Hone Heke, a Ngapuhi chief, chopped down the pole carrying the British flag at Kororareka (now Russell) in 1844 amid growing resentment at his people's treatment.

The flag was replaced four times and each time Hone Heke chopped it down.

It eventually escalated to an all-out attack on the town and the land wars began.

The flagstaff piece has a guide price of between $20,000 and $30,000.

Among other items at the auction on April 8 is a 19th-century wooden buggy carriage that was found in a farmer's shed at a small settlement near Nice in France 15 years ago.

It is expected to fetch between $4000 and $8000.