The Taiwan Affairs Office of the State Council denied any knowledge of an alleged "espionage" case to the Global Times Monday, in which three retired Taiwan armed forces officers have been arrested on suspicion of leaking information to Chinese mainland intelligence officers.

Yang Yi, spokesman for the Taiwan Affairs Office, declined to make any further comment. 

David Lo, spokesman of Taiwan's "Defense Ministry", said Monday that Chang Chih-hsin, the former "political warfare head of Taiwan's meteorology and oceanography office," and two other former officers had been arrested, AP reported.

"Chang, who initiated contacts through some retired Taiwan military intermediaries with Chinese mainland officials while serving in the navy, is suspected of luring his former colleagues and making illegal gains," the statement said.

It added that Chang was placed under investigation immediately after reports about his activities were received on him in March.

According to the newspaper, the 45-year-old Chang retired from the navy in May and a total of eight retired officers had been arrested.

The official statement said that Chang had leaked no confidential information, and that no active military personnel were involved.

However, the Taipei-based Apple Daily cited a retired senior Taiwan navy officer as saying that Taiwan's meteorology and oceanography office had access to maps that are crucial for submarine warfare.

According to the source, should armed conflict break out between Taiwan and the mainland, Taiwan's submarines "would face certain death" if these maps were leaked to the mainland.

Li Jie, a researcher at the Chinese Naval Research Institute, told the Global Times Monday that Taiwanese media had overstated the seriousness of the allegations, even if the leaks were true. 

Li stated that the location of submarines' planned operation zones "could be roughly deduced, among other measures, from the training and drills conducted by the Taiwan navy," he said.

Taiwan operates a small force of four submarines, but only two of these, bought from the Netherlands in the 1980s, could be operational in wartime. The two others were built by the US and date back to World War II.

Li Fei, a professor of Taiwanese studies with Xiamen University, said that the episode "would not harm the overall situation of peaceful and stable development" of cross-Straits relations, which have seen great improvement since Ma Ying-jeou became the leader of Taiwan in 2008.