A former top Taiwanese negotiator on China policy on Thursday rejected allegations he was spying for China, after he was forced to step down over suspicions of leaking secrets.

Chang Hsien-hao, ex-deputy minister at Taiwan's Mainland Affairs Council, resigned last week and has been put under investigation over suspicions of leaking confidential work-related information, according to the council.

Taiwan's United Daily News quoted unnamed officials at the Investigation Bureau, which is probing Chang, as saying that he is suspected of being a spy for China and allegedly leaked secrets including Taiwan's bottom line in negotiations to Chinese officials.

Chang has vehemently defended himself and insisted that he followed the instructions of his superiors in dealing with China during his two-and-a-half-year term as deputy minister. He pledged to cooperate with the investigation to clarify the truth and clear his name.

"There are many open or private channels of negotiation or communication between the two sides. I was only one of the pawns who followed instructions," he told a press conference.

Chang said he regretted that "a few people" risk damaging the recently warming cross-strait ties by accusing him of being a spy for China.

"How can the two sides continue to negotiate and communicate when I am persecuted and pinned with such a big crime? The mutual trust between the two sides would be completely gone ... and relations would freeze and regress," he warned.

Chang compared himself to the victims of "white terror," which refers to a period of oppression in Taiwan under the authoritarian rule of the Nationalists when some dissidents were persecuted as spies for Chinese communists.

Taiwan and China split in 1949 after a civil war, although Beijing still considers the self-ruled island part of its territory awaiting reunification, by force if necessary.

However, ties between the former bitter rivals have improved markedly under Taiwan's Beijing-friendly President Ma Ying-jeou, leading to the signing of 21 trade and other agreements since he took office in 2008.

In response, Chang's former superior Wang Yu-chi reiterated in a statement that he notified Chang of a tip-off accusing him of leaking secrets and asked the latter to leave and face the investigation.

The Investigation Bureau, which is tasked with countering Chinese espionage as well as criminal activity, declined to comment on the spying claim against Chang.

The scandal came after China's top official in charge of Taiwan affairs, Zhang Zhijun -- the most senior Chinese official ever to visit the island -- paid a landmark four-day visit in June.

Some observers said Chang's removal could complicate Ma's pro-Beijing push, which has already been hampered by major student-led protests in Taipei against a trade pact earlier this year.