HONG KONG -- Sotheby's will auction a bronze horse head that French troops stole from Beijing's imperial Summer Palace in 1860 and the auction house said Wednesday it expects the piece to fetch more than 60 million Hong Kong dollars (US$7.7 million; £á6 million).

The current owner, an unidentified Taiwanese collector, paid around 200,000 British pounds (US$400,000; £á300,000) for the bronze relic in 1989 at a Sotheby's auction in London, said Nicolas Chow, Sotheby's chief of Chinese Ceramics and Works of Art.

The piece is one of 12 animal heads from the Chinese zodiac that formed part of an elaborate water clock fountain designed by Jesuit missionaries, says Sotheby's. The 12 heads marked time by spouting water.

The Chinese government says the heads were looted by British and French troops during the second Opium War in 1860 from Beijing's Yuan Ming Yuan, also known as the Old Summer Palace, and should be returned.

Sotheby's lawyers say the Oct. 9 Hong Kong auction of the horse head is legal, although Chow said in a separate statement the auction house hopes the item "will be repatriated to China."

Sotheby's says only seven of the 12 animal heads have been located. The auction house says the state-linked Poly Art Museum in Beijing holds the tiger, monkey, ox and boar heads, while the rabbit and rat are part of a private European collection.

Chow said French troops took the horse head back to France where it was sold in the early 1860s.

He said the piece resurfaced in 1989, when its current owner bought it.

The Chinese government has previously spent over US$4 million (£á2.95 million) to buy back three of the heads -- the tiger, ox and monkey -- at auctions.

Chow said there has been strong interest among Chinese collectors for historical works of arts in the past three or four years, and Sotheby's had encouraged the bronze horse head owner to put it on the market again. Sotheby's has been in talks with Chinese collectors and institutions that Chow declined to identify. None of them have offered a bid ahead of the auction.

Poly Art Museum had no immediate comment on the auction, said staff member Gu Zun.

The bronze head will be auctioned with other pieces traced to imperial palaces from China's Qing dynasty (1644-1911), including imperial seals and paintings made by Jesuit missionaries.