A pair of pearl earrings which were discovered in a desk drawer may see bids in the region of £500,000 ($805,569) in an upcoming auction.

The stunning earrings were discarded to the depths of the drawer by the owner, who apparently did not like them.

They were then consigned to the auction by the owner's nephew, who casually mentioned them when selling other items through the Salisbury, UK auctioneers.

"The couple had no idea of their value and never gave them a second thought. They were blown away when I told them the estimate," said the auction house's Jonathan Edwards.

The consigner would have been even more blown away when the provenance of the earrings was revealed. They were a gift from King Carol II of Romania to his mistress, for whom he abdicated his throne in 1925. Together, the King and his lover spent the next five years living in exile in Portugal.

The earrings were then left to an unnamed British friend in Portugal (presumably the consignor's aunt) by the King's mistress following her death in 1977.

The incredible lot has been given a pre-sale estimate of £80,000-120,000, but Edwards has said they could bring five times that amount given their fascinating provenance and the current boom in the market for jewellery.

The auction is to take place in Salisbury tomorrow (April 26, 2012) with the earrings already attracting international interest.

Both Christie's and Sotheby's held Magnificent Jewels sales in New York last week, achieving impressive results. The Christie's sale also saw a new record set for the most expensive pink diamond sold in the US.