A former Taiwanese premier's account on popular Chinese microblogging site Sina Weibo went down on Wednesday, a day after he posted a message about freedom of expression, his office said.
Frank Hsieh, former chairman of the China-sceptic Democratic Progressive Party (DPP), opened his account on the Twitter-like website this month and quickly drew more than 60,000 followers.
On Tuesday he wrote that "freedom of expression is judged not by if one is free to criticise government officials in power but by if one loses freedom following the criticism".
By Wednesday, attempts to reach his page were met with a message saying the site was "not available for the moment."
Lin He-ming, an assistant from Hsieh's office, told AFP that Internet company officials in Taiwan said they are looking into the problem but found no technical explanation for the interruption.
China's far-reaching censorship authorities block or delete online content deemed to be too sensitive, under a system known as the Great Firewall of China.
Beijing has also been accused recently of mounting sophisticated cyberattacks on US firms.
Tensions between China and Taiwan soared when Hsieh's DPP ruled the island in the eight years to 2008 but have eased markedly since Ma Ying-jeou of the China-friendly Kuomintang took power that year.
Hsieh travelled to China in October, making him the most senior DPP politician ever to visit the mainland.