London: Rare 10-rupee banknotes found drifting from a shipwreck in 1918, en route from Bombay to London, will be auctioned next Wednesday.

Noonans Mayfair auction house will feature the notes in their World Banknotes sale, with an estimated value between GBP 2,000 and 2,600. Recovered from the wreckage of the SS Shirala, which was torpedoed by a German U-boat on July 2, 1918, the two 10-rupee banknotes are dated May 25, 1918.

"Whole blocks of these notes, along with lots of provisions ranging from marmalade to ammunition, were on their way to Bombay from London when the boat was sunk by a German U-Boat," said Thomasina Smith, Worldwide Head of Numismatics at Noonans.

"Many notes floated to shore, including unsigned 5 and 10 Rupees, and signed 1 Rupees – one of which also features in this auction. Most were recovered and subsequently destroyed by the authorities and new ones were printed to replace them, however a very few examples remained in private hands," she said.

The expert says she has never seen notes like these before and that they only came to light after the Bank of England mentioned the 1918 shipwreck on social media.

"These are in very good condition – they must have been in the middle of a tightly bound bundle, so didn't make contact with the sea. It's also wonderful that they bear consecutive serial numbers," she said.

Another auction at the World Banknotes event next week is a rare 100-rupee note from the British colonial era in India. It's expected to fetch between GBP 4,400 and 5,000. The note, signed and stamped in Calcutta, dates from 1917 to 1930. On its back, you'll find "100 rupees" written in different Indian languages like Hindi and Bengali.