Authorities at Beijing's Yuanmingyuan Park (formerly the Old Summer Palace) have issued a carefully worded statement opposing the auction in France of a jade seal from Emperor Qianlong's reign and appealing for the return of all cultural relics looted from China. The seal, part of a collection belonging to the descendants of French general Elie Jean de Vassoigne, was to go under the hammer at the Paris-based auction house Beaussant Lefevre yesterday. Zong Tianliang , a Yuanmingyuan Park spokesman, said ample documentation was available to show that the seal had been part of a collection at Yuanmingyuan before the palace was ransacked by British and French troops during the second opium war in 1860. However, Mr Zong refrained from saying that the item had been stolen. 'We once again express our strong indignation over such acts, because they hurt the feelings of the Chinese people and undermine the cultural well-being of the Chinese people, as well as contravene international treaties,' he said. Some analysts say the mainland's cultural heritage authorities must produce proper records or documents tracing such items to their origins to prove they were stolen. Mainland newspapers said general de Vassoigne, once a colonel stationed in a port outside Tianjin , had led the sacking forces. The auction of two looted bronze animal heads in Paris by Christie's in February drew fierce public reaction.