About 1,200 birds have been impounded for two months in dispute over import duties

Belgium's ambassador to Beijing is in talks to free more than 1,000 racing pigeons detained by Chinese authorities in a dispute over import duties.

Officials impounded 1,600 birds that had been sold to Chinese enthusiasts at auction in Belgium. The captives initially included Bolt, bought for a world record price of €310,000 (£260,000), but he and about 400 others have been released following negotiations.

Didier Reynders, Belgium's deputy prime minister and foreign minister, said the country's ambassador was engaged in mediation to free the remaining birds, which have been held for two months.

Pigeon-keeping was banned in China for many years, being regarded as a bourgeois decadence, but like other traditional pastimes it has resurfaced as a popular – if pricey – hobby.

Sun Yan, deputy director of the Beijing Changping district racing pigeon association, said the last national survey, in the 1990s, had found 300,000 pigeon fanciers in China, and numbers had increased vastly since then. One race due to take place soon in Beijing offers 23m yuan (£2.3m) in prize money.

In 2009, Wang Qishan, now one of China's top leaders as a member of the politburo standing committee, visited one of Belgium's premier breeders, Jos Thoné, who offered him two birds as a gift after Wang said his uncle was an enthusiast.

But pigeons are usually banned from flight in Beijing at sensitive times, such as when big political meetings are taking place. Bird flu fears have also led to race cancellations and the vaccination of tens of thousands of birds.

Chinese import duty would normally be 10% of the value of the birds, plus a 13% tax. Authorities complained that the birds had been declared at only nominal values despite their high price tag.

Bolt, named after the Olympic gold medallist Usain Bolt due to his speed, was bought by a Chinese businessman in May at an auction by the Belgian pigeon traders Pipa. The company's chief executive, Nikolaas Gyselbrecht, flew to Beijing to negotiate his release.

Chinese officials agreed that Pipa was not at fault and released 400 birds to their buyers for a symbolic sum, rather than the €1m or more that would otherwise have been due, Gyselbrecht said. He said officials from the two countries hoped to simplify the negotiations by finding a single party to represent the various buyers of the other birds.

Bolt cannot race in China because he would try to head back to Belgium, so he will be used for breeding. "He will have a good retirement. He will have a very nice pigeon loft and he will see a lot of female pigeons," said Gyselbrecht.