Mr. Wang’s allegations seem certain to reverberate widely in Taiwan, in Hong Kong and on the mainland. Although China’s intelligence operations in Taiwan and Hong Kong have long been presumed to be robust, the statement provided an extraordinary amount of detail.

“We had an inkling this was happening, but we have never had evidence or an insider’s account,” Adam Ni, a researcher at Macquarie University in Sydney who has been recently working in Taiwan, said in a telephone interview.

With the elections in Taiwan, for example, Mr. Wang described how the separate branches of China’s military divided up their labors.

Mr. Wang said intelligence efforts included creating more than 20 media and internet companies to launch “targeted attacks,” and spending roughly $200 million over an unspecified period to invest in television stations in Taiwan. His statement did not explain how such a large sum of money failed to be noticed or raise alarms.

The disclosures could also further sour relations between China and Australia, which recently passed a law seeking to rein in foreign interference after several wealthy Chinese businessmen tied to Beijing were accused of trying to manipulate Australian politics.

One of those businessmen, Huang Xiangmo , was a successful developer who had his Australian residency canceled in February. According to Mr. Wang’s statement, Mr. Huang led a group of Australian state and local lawmakers to visit Hong Kong, where they met with Mr. Wang’s boss, a man named Xiang Xin. Mr. Huang, who has previously rejected the claim that he has tried to interfere in Australian politics on behalf of Beijing, could not be reached for comment.

These kinds of connections between Australian lawmakers, Chinese wealth and officials whose Communist Party ties are masked by big business have put much of Australia on edge. Earlier this week, the former head of Australia’s main foreign intelligence agency described China’s espionage efforts as “insidious.”