Singapore released a citizen from detention more than a year after he pleaded guilty in a U.S. court of spying for Beijing with the city state’s government saying the threat he posed as a foreign agent has now been "effectively neutralized.”

Dickson Yeo was arrested in Singapore in December last year and later detained under security laws for acting as a paid agent of a foreign state, the government said on Tuesday. He was released after investigations determined that he wasn’t able to obtain or pass on any classified information from Singapore to his foreign handlers.

"The threat that Yeo poses as a foreign agent is assessed to be effectively neutralized. As such, he does not pose a security threat that warrants continued detention,” according to a statement from the Internal Security Department, which comes under Singapore’s Home Ministry.