Beijing - Chinese lawyers said Wednesday that they plan to challenge the auction in France of two bronze animal heads that were allegedly stolen from Beijing's former Summer Palace by British and French troops 150 years ago.

The lawyers were trying to get the Chinese bronze heads withdrawn from a huge Yves Saint Laurent art collection scheduled to be auctioned by Christie's in Paris next week.

"If they still want to hold an auction, we will go to court," Xie Tongxiang, one of the leaders of a group of Chinese lawyers planning to travel to Paris, told Deutsche Presse-Agentur dpa.

"The treasure was looted by them [French and British troops] in 1860, which is recognized by everyone, even the collector himself," Xie said.

Christie's last week said the auction of the heads would proceed despite mounting objections from Chinese people in mainland China, Hong Kong and Taiwan.

The bronze rat and rabbit heads are believed to be part of a set of 12 representing the animals of the Chinese zodiac.

They were cast in the late 1750s and displayed at the former imperial Summer Palace during the late Qing dynasty (1644-1911).

The 12 heads were believed to have been looted in the razing of the palace by a British- and French-led force from eight foreign powers during the second Opium War.

In 2007, the last time one of the bronzes came up for auction, Macao-based billionaire Stanley Ho bought the horse's head pre-auction for about 9 million dollars and donated it to the Chinese government.

Five of the animal heads are now in China, according to the Chinese media, while the location of the other five remained unknown.

Xie and other lawyers are working to stop the sale and are not willing to negotiate a private agreement to buy the rat and rabbit heads, he said.

The directors of the Old Summer Palace, known in Chinese as Yuanmingyuan, would decide later this week if they would join the action to stop the auction of the heads, Xie said.

China's Foreign Affairs Ministry last week said the bronze heads were "precious cultural treasures which were looted by the joint Anglo-French forces."

"China has incontrovertible ownership of those objects, which should be returned to China," ministry spokeswomen Jiang Yu told reporters.

"Auctioning cultural objects looted in wartime not only offends the Chinese people and undermines their cultural rights but also violates relevant international conventions," Jiang said. (dpa)