Authorities in Hong Kong have refused to renew a work visa for a Taiwanese representative to the special administration region in another sign of the frosty relations across the Taiwan Strait. Tsai Meng-chieh, who works for Taiwan ’s Investigation Bureau, was forced to return home on Wednesday after the city government refused to extend his papers, according to officials from the bureau and the Mainland Affairs Council. “Tsai, whose visa was due to expire [on Wednesday], applied in July to extend his visa, but was told last week that his working visa would be discontinued,” a council official said. Tsai, who is deputy section chief of Taiwan’s representative office, in December became the first investigator from the self-ruled island to be sent by the bureau to Hong Kong. Taiwanese officials said at the time his move signalled the mutual trust and judicial cooperation between the two sides. Tsai, who received training from the US Federal Bureau of Investigation, is credited with coordinating the work of Taiwanese prosecutors and US Immigration and Customs Enforcement officials to crack a criminal gang involved in telecoms fraud in the US and having the suspects returned to Taiwan, the Investigation Bureau said. Bureau officials would not speculate on why the Hong Kong authorities refused to extend the visa. “Tsai has respected all local laws and regulations during his tenure in Hong Kong,” one said. Hong Kong cancels National Day fireworks over protests The Mainland Affairs Council on Wednesday expressed its regret at the decision and described it as politically motivated. “The council has many times urged the Hong Kong government to deliver its tasks based on the practical need to uphold the public well-being and safety of the people of Taiwan and Hong Kong, and extend the working visa for Tsai accordingly, but the Hong Kong government still rejected our request,” it said in a statement. Since the start of the protests in Hong Kong in June, Taiwan’s President Tsai Ing-wen has repeatedly expressed her concern, saying Taipei would do all it could to help protesters seeking shelter in Taiwan. Beijing has warned Taiwan against offering asylum to the protesters and said it would not tolerate any attempt by Taipei to meddle in the city’s affairs. Ma Xiaoguang, a spokesman for Beijing’s Taiwan Affairs Office, has criticised the island’s president for offering shelter to activists from Hong Kong, saying it would not only make Taiwan a haven for criminals but would also put the well-being of the Taiwanese public at stake. Ma has also accused Tsai’s Democratic Progressive Party of being “blind to the criminal acts of certain violent activists” and of trying to “cover up their crimes by fanning further fiery action in Hong Kong”.