A traditional Korean garment worn by Jimin of K-pop boyband BTS will go on auction today (April 22) and it has sparked outrage among fans because it will be sold unwashed.

The hanbok was worn during an energetic pre-recorded performance by the band for The Tonight Show Starring Jimmy Fallon in September last year. The memorable showcase was filmed at the historic Gyeongbokgung Palace in Seoul.

"Jimin's hanbok is a work of art that is unique. It was left unwashed after the performance and will be sold with Jimin's body odour intact," said a spokesman from the Myart Auction, which is holding the auction online from April 22 to 29.

Also on auction are 50 works of modern and ancient Korean art.

The traditional-meets-modern hanbok was designed by costume designer Kim Rieul and loaned out for the performance.

Fans of BTS, known as Army, have blasted both the designer and the auction house, saying that selling the unwashed item was "creepy", "unhygienic" and "commodifying" Jimin's sweat.

Bidding will start at 5 million won (S$5,950). Despite the ick factor - or perhaps because of it - the final bid is expected to be much higher.

In January last year, the seven microphones used by the seven-member band during their Love Yourself tour from 2017 to 2019 sold for US$83,000 (S$110,000).

More recently, in February, the pastel ensemble that the Grammy-nominated band wore in the Dynamite music video sold for US$162,500, more than eight times its original estimate.