Five rhinoceros horn cups which had the highest ever estimate on the US version of the Antiques Roadshow could fetch $1m (£630,000) when sold at auction.
The cups first came to light in June 2011 after appraiser Lark Mason valued the five caved rhinoceros horn between £630,000 and £945,000 - the highest ever estimate on the show.
They are now set to be sold at Sotheby's auction in New York on March 20 where it is estimated the set will fetch between £445,000 and £636,000 with individual cups valued between £75,000 and £150,000.
"They are in superb condition and represent a fine and comprehensive group that showcases the different styles of these extraordinary objects," Sotheby's said in a statement.
Douglas Huber, a Vietnam veteran from Oklahoma, brought his collection of Qing Dynasty carved rhinoceros cups to a filming of the show in Tulsa, Oklahoma in 2011.
Huber had been collecting the cups since 1969, one of which he purchased from Sotheby's in 1977.
The highlight of the group is an "eight Immortals" rhinoceros horn cup from the Qing Dynasty, 17th-18th century, which Sotheby's expects to have a higher starting price than the other four cups at £113,000.
"I have kind of been following prices of rhinoceros horn cups and they kind of skyrocketed," Huber told the Tulsa World newspaper.
"They are being bought up by the Chinese," he added. "I didn't buy them for investment but for the rarity of them and the beauty."
Huber paid just over £3,000 total for the cups.