A family living in Berkshire county in England have found out that a cache of arms kept in their attic, are artefacts taken by their ancestor, a British army officer, from the palace of Mysore ruler Tipu Sultan in the 18th century. The items could sell for millions of pounds, Metro reported on Thursday.

The cache of arms includes a gun that Tipu Sultan used during his last battle against the British forces in 1799, the newspaper reported. The gun has a tiger stripe pattern, and also shows damage from a musket ball, which allegedly killed the ruler, the website added.

Apart from this, the collection includes a gold-encrusted sword belonging to Tipu Sultan’s father, Hyder Ali Khan, Mysore’s ruler before Tipu, and a gold snack box with three nuts still inside it.

Major Thomas Hart, an officer of the erstwhile British East India Company, brought the weapons to the United Kingdom following the Fourth Anglo-Mysore War in 1798-99, according to Metro. They now belong to a family who are descendants of Hart.

Auctioneer Anthony Cribb said the items would be more valuable than previous Tipu Sultan artefacts sold in the United Kingdom in 2016 for £6 million (Rs 55.1 crore). “It is impossible to put a price on these items but I would say this collection is more important than the previous one that sold,” he said. “That one was put together over 40 years and came from lots of different places. But these weapons were picked up at the battlement by a military officer who was there and have been in the same family for 220 years.”

Cribb called the gun a “once-in-a-lifetime find”. “I nearly fainted when I first saw it,” he told the daily. “The owners are just an ordinary family who live in a Victorian semi-detached house. You could describe this find as a lottery win for them.”

It is not known when the items will likely be auctioned.