A US citizen has been sentenced in North Korea to ten years hard labour after being found guilty of espionage and "subversion of the DPKR social system."

Kim Dong-chul, who immigrated to the United States from Seoul in 1972, was guilty of "slandering the supreme leadership, plotting to subvert the DPRK system and gathering state and military secrets for espionage," according to state media.

Mr Dong-chul, 62, allegedly carried out propaganda against North Korea after establishing Dongmyong, a company based in Rason - a special economic zone in North Hamgyong Province of the DPKR - in 2008.

The prosecutor accused him of colluding with several South Koreans in 2013 to collect top party, state and military secrets, including nuclear facilities, nuclear tests and photographs of warships.

He was arrested last year after receiving an USB stick that allegedly contained photos of local markets in Rason and documents containing information relating to nuclear programs.

Mr Dong-chul was paraded in front of state media and confessed to the charges.