"The sweater’s been tucked away in an attic for more than 40 years," Frank Everett, Sotheby’s senior VP and sales director for jewelry, told "Today" on Wednesday. "We love a discovery story in ...

The sweater, which has an estimated price of $50,000 to $80,000, will be on display at Sotheby’s New York showroom from Sept. 7-13. Online bidding opens Aug. 31 and runs to Sept. 14.

Designers Sally Muir and Joanna Osborne pose with their Black Sheep Sweater worn by Lady Diana Spencer on the first day it is displayed at Sotheby's on Sept. 7, 2023 in New York City.

According to the auction house, bids for Diana's original red sweater covered with dozens of white sheep -- and one black one -- will be taken from Aug. 31 to Sept. 14.