Christian Solidarity Worldwide says it is "gravely" concerned for the future of two American journalists who have been condemned to 12 years of hard labour in North Korea.

A report from North Korea's official Chosun Central News Agency (KCNA), which said that Laura Ling and Euna Lee were sentenced in the last week to 12 years of “reform through labour” after being found guilty of “crimes against the state and illegal border crossing”.

Ling, a Chinese American, and Lee, a Korean American, were arrested by North Korean border guards while on a reporting trip along the Chine-North Korea border. They were working at the time for Current TV, a video news website chaired by former US Vice President Al Gore.

While the facts surrounding the case remain unclear, the North Korean official news agency, KCNA, claimed Ling and Lee “were detained on March 17 while illegally intruding into the territory of the DPRK by crossing the DPRK-China border”.

The US has called for the immediate release of the women, saying the charges are “baseless”. North Korea has so far dismissed the calls.

CSW, which works with the persecuted church worldwide, has expressed concern over the safety of Ling and Lee in what it describes as North Korea’s “macabre imprisonment system”.

In its recent report, 'North Korea: A Case to Answer - A Call to Act', CSW reported that some 200,000 political prisoners were being held in the country’s labour camps. Inmates, the group warned, were often subject to “the most dire living and labour conditions”.

CSW also said it had found "indicators of genocide" against religious groups, particularly Christians.

Tina Lambert, CSW’s Advocacy Director, said it was “highly unlikely” that the women had received a fair trial.

“We call upon the North Korean regime to rescind this unjust sentence and to grant Laura Ling and Euna Lee’s immediate release,” she said.

“We are deeply concerned for all prisoners subjected to severe conditions in the country, including grueling labour, minimal food rations and desperate living conditions.

“Such treatment is indicative of the total disregard of the regime towards human rights.”

Ms Lambert urged the United Nations to “boldly condemn and extensively investigate these concerns at all levels of its system, including the Security Council, as a matter of utmost importance”.