North Korean state media said the missionary -- called Kim Jong Uk in the North but previously called Kim Jung Wook in the South -- was tried yesterday and admitted to anti-North Korea religious acts and "malignantly hurting the dignity of the supreme leadership of the" North.
North Korea said in a dispatch dated yesterday that Kim had defence counsel but the details of the trial could not be independently confirmed.
North Korea's constitution guarantees freedom of religion, but in practice only sanctioned services are tolerated by the government. Defectors from the country have said that the distribution of Bibles and secret prayer services can mean banishment to a labour camp or execution.
North Korea said the man was arrested last October after crossing into the country from China. Kim appeared on North Korean TV in February and said he received assistance from South Korea's intelligence agency and apologised for committing "anti-state" crimes.
Last year, North Korea sentenced American tour operator Kenneth Bae to 15 years of hard labour for committing "hostile acts" against the country.
Tensions are running high between the rival Koreas. North Korea has conducted a string of recent missile and artillery tests and unleashed hostile rhetoric insulting the leaders of the US and South Korea.