A panel of experts mandated by the UN's Human Rights Council said North Koreans had suffered "unspeakable atrocities".

The panel heard evidence of torture, enslavement, sexual violence, severe political repression and other crimes.

It is expected to recommend an inquiry by an international court or tribunal.

The BBC's Imogen Foulkes in Geneva says the report is expected to be one of the most detailed and devastating ever published by the United Nations.

Testimony to the panel has included an account of a woman forced to drown her own baby, children imprisoned from birth and starved, and families tortured for watching a foreign soap opera.

The full report is expected to contain hundreds of pages of further evidence of a nationwide policy of control through terror, says our correspondent.

The cult of personality surrounding the Kim family is as strong as ever in North Korea

Sunday saw commemorations of the birthday of Kim Jong-il, who died in 2011

Away from the choreographed celebrations, images showed few people on the streets of Pyongyang

The Associated Press quoted from a leaked version of the panel's report, which accuses the regime of taking decisions aimed at maintaining its own rule "in full awareness that such decisions would exacerbate starvation and related deaths amongst much of the population".

For years, North Korean defectors have detailed harrowing accounts of life under the brutally repressive Kim dynasty.

The regime keeps tens of thousands of political prisoners in camps, and divides the population up in terms of presumed loyalty to the regime.

Civilians live under a system of neighbourhood surveillance where they are encouraged to denounce each other, according to defectors.

Although this information has been in the public domain for years, the panel's inquiry is the highest-profile international attempt to investigate the claims.

North Korea refused to participate and has rejected any claims of rights violations and crimes against humanity.

Since Kim Jong-un took over, his regime has threatened nuclear war and conducted a deadly purge

According to AP, which has seen an outline of the report's findings, the document will conclude that the testimony and other information it received "merit a criminal investigation by a competent national or international organ of justice".

However, China would be likely to block any attempt to refer the North to the International Criminal Court.

And an ad-hoc tribunal like those set up for Rwanda, Sierra Leone or Cambodia would appear unlikely without any co-operation from elements within the country.

The panel will formally present its findings in March, when the Human Rights Council will decide which recommendations to support.