New York - North Korea's abuses against its own citizens are so horrific that they compare to some of the darkest chapters of modern history, from Nazi Germany to Cambodia's Khmer Rouge and apartheid-era South Africa, a UN investigator says.

The retired Australian judge, James Kirby, addressed the UN rights body in Geneva on Monday, urging diplomats to act against what he called a "totalitarian state that does not have any parallel in the contemporary world".

Kirby and several major rights groups are pushing for tough action against North Korea - perhaps even a criminal probe that lands its youthful leader, Kim Jong-un, in the dock of the International Criminal Court (ICC).

While North Korea is shielded from global opprobrium by its long-standing ally, China, activists point to shifting sands in the regional political landscape that suggest Pyongyang is losing favour.

"Contending with the scourges of Nazism, apartheid, the Khmer Rouge and other affronts required courage by great nations and ordinary human beings alike," Kirby told the UN Human Rights Council. "It is now your duty to address the scourge of human rights violations" in North Korea, he said.

His report details evidence from hundreds of witnesses about killings, enslavement, torture, imprisonment, rape and forced abortions in North Korea, which were gathered during emotionally charged public hearings in Seoul, London, Tokyo and Washington.

Gulag nation



The report included testimony from people who fled North Korea after being inside political prison camps, which hold as many as 120,000 inmates. One former captive gave a harrowing account of how she was forced to drown her newborn baby.

The United States, Japan and European governments are working to push the evidence to the UN Security Council, which can refer alleged abuses in North Korea to the ICC, a war crimes court in The Hague. But that is where any serious initiative would grind to a halt. China has a permanent seat on the Security Council and has a track record of using its veto to quash such actions by the 15-nation body.

During the debate in Geneva this week, China's diplomat Chen Chuandong rejected the report, saying Kirby's commission levelled unfounded accusations and made recommendations that were "divorced from reality". A lack of support and cooperation from Pyongyang made it "impossible for the commission to carry out its mandate in an impartial, objective and effective manner", Chen added.

Rights groups blast Beijing for protecting Pyongyang, and for sending back North Koreans who have escaped across China's southern border. "Will China vote for continued concentration camps?" asked Peter Splinter, from the UK-based rights group Amnesty International. "I fear they will. But they are on the wrong side of history. This report is too powerful to slip below the waves."

A personal call for action came from Shin Dong Hyuk, who was born in the gulag and escaped after his mother and brother were executed. He said that "hundreds of thousands of political prisoners are waiting for their death" in the dynastic communist state.

Julie de Rivero of Human Rights Watch said China should abandon North Korea in much the same way that it gradually withdrew diplomatic cover for Sudan over its alleged atrocities in Darfur.

"We cannot go on pretending that North Korea cannot be acted upon. This is the first step in a process that will see perpetrators brought to justice," she said. "Yugoslavia's Slobodan Milosevic and Charles Taylor of Liberia eventually faced justice, but that was only after a lengthy process."

China's protection



Although China backed UN sanctions against North Korea over nuclear weapons tests, it shields Pyongyang from most foreign meddling, fearing regime collapse, a potential refugee crisis and South Korean and US forces on its doorstep.

But China may distance itself from North Korea as it pursues a more active foreign policy in the region and asserts territorial rights in the East China Sea, said Angela Stanzel, an analyst at the European Council on Foreign Relations.

Beijing's allegiance to Pyongyang is strained by the erratic behaviour of Kim Jong-un, who took over from his father in 2011. The young leader has raised the tenor of North Korea's trademark rhetoric against its "enemies" in South Korea, Japan and the US.

The execution of the leader's uncle, Jang Song Thaek, left Pyongyang watchers guessing about power struggles late last year. This month, a North Korean missile test that flew dangerously close to a Chinese passenger jet raised further questions about Beijing's ties to Pyongyang.

"North Korea has made threatening gestures for years, but its relatively new leader, Kim Jong-un, is increasingly unpredictable. This poses a problem for China as it presents the danger of imminent conflict on the peninsula," said Stanzel. "As China becomes more isolated, there is an opportunity for Europe, Japan, South Korea and the US to gang up on China and pave the way for a next phase of negotiations with Pyongyang. But even this is a long way off."

Other analysts see less scope for change. Scott Snyder, of the US-based Council on Foreign Relations, said China's near-certain veto will leave Washington unable to deliver anything other than "symbolic measures" against Pyongyang.

"The effect of taking this up under circumstances where China opposes it will be to criticise both Beijing and Pyongyang at the potential cost of closer US-China cooperation on other North Korea-related issues, thereby raising the political costs to China of support for North Korea, but probably not enough to change China's mind," he told Al Jazeera.

Do sanctions work?



Others are more pessimistic still. Jim Hoare, a former British envoy who served in Pyongyang, said high-profile diplomatic overtures will do little to persuade Beijing or compel Pyongyang to free political prisoners.

"What is really new in this report? Very little, but another trawl through the usual defectors and interest groups. It has all been known for years. Is the North Korean human rights issue being used more because of the nuclear issue? I suspect so," Hoare said.

"And will sanctions work? North Korea has been sanctioned since 1950 - it hurts their pride, perhaps, but there are enough countries and people in the world who are willing to help them evade sanctions. If there is money to be made, people will try to make it."

Follow James Reinl on Twitter: @jamesreinl