Christian Solidarity Worldwide (CSW) is calling upon North Korea to end the "brutal" oppression of its citizens following the death of its leader Kim Jong-il.
Official state media said the dictator died of a heart attack. It has broadcast footage showing distraught North Koreans publically mourning his death in Pyongyang.
With the world watching to see what becomes of North Korea under the "Great Successor", his third son Kim Jong-un, CSW said there was an opportunity for the country to change direction as it hit out "crimes against humanity" being perpetrated by the regime.
These include the torture and "degrading" treatment of inmates in prison camps and summary executions, which it said were "common".
With no religious freedom in the oppressive communist country, CSW said Christians were being executed for their beliefs.
CSW’s Chief Executive Mervyn Thomas said, “There is now a real opportunity for North Korea to change direction, end its isolation, stop the brutal oppression of its own people and open up to the world."
It wants North Korea to allow the UN Special Rapporteur on Human Rights to visit their notorious prison camps.
"CSW urges the North Korean regime to take the initiative at this unique moment in time in order to introduce fundamental changes and close the prison camps, end torture, slave labour and summary executions, respect religious freedom and release all prisoners of conscience," said Mr Thomas.
"The international community should seize the moment to press for these changes.”
The organisation has campaigned for more than a decade against human rights atrocities being committed by the North Korean regime.
In September, CSW helped to establish the International Coalition to Stop Crimes Against Humanity in North Korea (ICNK), incorporating 40 global human rights organisations, including Amnesty International, Human Rights Watch and the International Federation for Human Rights.