The EU ambassador to China has called for the release of Gui Minhai, a Swedish national who was among a group of booksellers detained in 2015 for allegedly spreading anti-China messages, after he was seized on a train in China at the weekend.
Mr Gui, who has published books on the personal lives of the Communist Party leadership, angering the central government in Beijing, was taken into custody by plainclothes officers as he travelled with Swedish diplomats on a train from Ningbo to seek medical treatment in Beijing for a neurological illness.
The EU ambassador to China, Hans Dietmar Schweisgut, told a news briefing he "fully supported" Sweden's efforts to resolve the issue.
"We expect the Chinese authorities to immediately release Gui Minhai from detention and to allow him to reunite with his family, to get consulate support and medical support in line with his rights, because he is a Swedish citizen and also a citizen of the European Union, " Mr Schweisgut said.
On Tuesday, Sweden's foreign minister Margot Wallstrom said she expected "the immediate release of our fellow citizen, and that he be given the opportunity to meet Swedish diplomatic and medical staff".
The Swedish foreign ministry has twice summoned China’s ambassador to Stockholm to explain the situation after he was seized.
Chinese foreign ministry spokeswoman Hua Chunying described the calls from Sweden and the EU as "baseless".
“Any country must respect the Chinese authorities’ handling of cases involving foreigners in China in accordance with the law,” she told a news briefing. She went on to say she had no new information about the case and knew nothing about it.
Mr Gui was one of five Hong Kong booksellers abducted in 2015 after the Causeway Bay bookshop where they worked was accused of publishing books that painted China's leadership in a negative light.
The case caused an international outcry as it highlighted the eroding state of press freedom in Hong Kong, which is guaranteed limited autonomy under the terms of the 1997 reversion to Beijing rule.
Mr Gui was apparently picked up by Chinese security officers while on holiday in Thailand, and later made what seemed to be a forced confession on Chinese state TV later that year. China later said he and the other booksellers had come to the mainland voluntarily.
He was jailed for two years for a traffic offence that took place in 2003, and was apparently freed late last year.
The Global Times newspaper, which tends to take a strongly nationalist line, accused western media of sensationalising Mr Gui’s plight.
“The western media still wants to wield their hegemonic discourse power to manipulate the judgment of sensitive information about China and therefore continue to attack China’s political system,” it said, adding that Mr Gui’s activities could not undermine China’s national interests.
“Western media reports are guided by ideological logic, but China follows legal reasons in handling its own affairs. This is a diversified world,” it said.