Supporters of Han Kuo-yu, who favours closer ties with Beijing, joining a rally in Taiwan last month. Pro-KMT media outlets are said to have received funds from China

Shortly before polls closed last Sunday in the Hong Kong elections that delivered a resounding rebuff to Beijing, a wealthy Chinese couple arrived at Taoyuan International airport in another territory China sees as part of its realm, Taiwan.

Xiang Xin and his wife, Kung Ching, went to check in at the airport outside Taipei for a flight home to Hong Kong. But they never made it past immigration. A screen alert popped up, their passports were confiscated and they were barred from leaving the island as suspects in possible national security violations.

The two business executives had just been named in explosive espionage allegations as bosses of a Hong Kong “front” company with a mission to interfere in Taiwan’s elections next month.

They had been