The family hopes the items of Tipu Sultan find their way back to India.
A grand flintlock gun and gold-encrusted sword are among eight rare artefacts evaluated as items from Tipu Sultan's armoury discovered by a couple in their attic in the English county of Berkshire.
The artefacts, brought back by Major Thomas Hart of the East India Company after the Tiger of Mysore's defeat at Seringapatam in 1799, are now set to go under the hammer at an auction later this month.
The items were passed down generations and could fetch millions of pounds for the unnamed family in whose home it was discovered.
"This is a very exciting discovery, made in an ordinary little home in Berkshire after lying wrapped up in an attic for 220 years," said Anthony Cribb, of Antony Cribb Ltd auctioneers who specialise in arms and armoury related sales.
"The family is not motivated by money and sincerely hopes these items find their way back to India, maybe to a museum, for future generations to have access to it," he said.
The auction house will put up all eight items for auction on March 26 as individual pieces, without any price estimates, due to the "special" nature of the discovery.
Mr Cribb said it was impossible for him to put a price to any of the items and would rather let the market and buyers decide.
The lots came to light in January this year when the couple contacted Anthony Cribb Ltd about a sword they had in their attic.
After an evaluation, a gold "Haider" symbol found on the sword confirmed that the sword belonged to Haider Ali Khan -- Tipu Sultan's father. Three other swords bearing similar gold markings were found soon after, along with a bayonet and gun.
"The gun is definitely the highlight as it not only bears the symbol of Tipu Sultan's armoury but is also battle-worn. There is a chance that this gun was among the weapons used by the ruler in his famous last stand against the British in the Anglo-Mysore battle," said Mr Cribb.
An intricately designed Betel Nut Casket and a shield belonging to Tipu Sultan as well as a Gold East India Company Seal ring belonging to Major Thomas Hart will also go under the hammer.
In 2014, a solid gold ring belonging to the 18th century ruler of Mysore had fetched 145,000 pounds at a Christie's auction in London and a collection of items associated with him sold at another auction for around 6 million pounds in 2016.