Important relics of Napoleon Bonaparte's last years, including a lock of hair believed to have been taken from his deathbed, have emerged from a New Zealand antique "roadshow".

Napoleonic scholars are looking forward to analysing the find, which also includes a lithograph taken from a drawing of the former French emperor made the morning after his death in 1821, at a conference in Malta in July.

"It's a fascinating collection and contains a lot of stuff that has great historical importance," International Napoleonic Society president and prolific author David Markham told the Herald from Washington State yesterday.

Items from the collection were shown to representatives of Auckland auction house Art+Object at a charity roadshow event held in February to raise funds for Rotorua's museum.

Managing director Hamish Coney said the collection was handed down through descendants of Denzil Ibbetson, a talented artist and chief commissary officer on the Atlantic island of St Helena, where Napoleon remained under British detention from 1815 until his death in 1821 aged 51.

He said the collection was brought to New Zealand by Captain Ibbetson's first son, Frederick, in 1864 and passed through three subsequent generations until the last member of its male line died several years ago.

The man kept it in a suitcase and his widow and children, who did not want to be identified, had decided the time had come to offer it for auction.

As well as the hair, held in a tightly-bound 2.4cm diameter circle and believed to have been taken by Captain Ibbetson as a "memento mori", the collection includes about 25 watercolour or pen depictions of Napoleon and key structures on St Helena, including the buildings where he was kept under virtual house arrest.

Mr Markham has received several images of items from the collection, and has offered to write an essay for a catalogue being prepared for its auction on June 29.

But what he is most looking forward to is poring over a transcript, which Mr Coney is trying to complete, of a diary containing close-hand observations of Napoleon by Captain Ibbetson during a six-week voyage to St Helena in August on HMS Northumberland, in 1815.