Taipei: Taiwan's Defence Minister has confirmed for the first time that tip-offs offered by the United States had helped crack the island's worst espionage case in 50 years, an official said on Tuesday.

Thanks to the US information, "It took only three months for the military and national security units to crack the case", Minister Kao Hua-chu said in parliament on Monday, according to his spokesman.

Taiwan authorities in January arrested Major General Lo Hsien-che over claims that he spied for China, reportedly after he was lured by sex and money offered by a female Chinese agent on a 2002-2005 posting to Thailand.

The 51-year-old was head of the Army's Telecommunications and Electronic Information Department, according to the Defence ministry, which said it was Taiwan's most serious espionage case in five decades.

The minister did not go into detail about the information that Lo may have leaked to China, nor did he say how the US authorities became alarmed.

Taiwan's newspaper cited an unnamed security source as saying that the US Federal Bureau of Investigation had come across Lo while probing another espionage case in the United States.

In that case, the FBI accused Kuo Tai-shen, a US citizen who was born in Taiwan, of obtaining secret military documents from Pentagon employee Gregg William Bergersen and passing them onto Beijing.