Kim Jong-un 'spent over $600m in a year' while North Korean citizens starved to death

North Korean dictator Kim Jong-un splashed millions of dollars on luxury items including dozens of pianos and Mercedes-Benz cars, a UN report has revealed.

The 372-page report said the country continues to allocate a "significant amount of state resources for the purchase and important of luxury goods" while hunger and malnutrition take a heavy toll on the population.

According to the report, North Korea's spending on luxury goods has more than doubled from an average of $300 million a year to $646 million in 2012, when Kim assumed control following his father's death, Kim Jong-il.

Kim reportedly treated himself to a dozen of luxury cars, top quality pianos and a private theatre for his closest allies and top aides.

These items violate UN sanctions imposed on North Korea prohibiting "the provision of luxury goods" adopted in 2007.

The report did not examine how the items were imported into the country.

A former North Korean official who managed to escape the country said Kim funded his lavish lifestyle by trafficking ivory from Africa to China and selling alcohol to Islamic countries.

The money was transferred into parallel funds outside of the state budget to cover "personal expenses of the Supreme leader, his family and other elites".

Revenue from criminal activities stood at $500 million a year in 2008, amounting to one third of North Korea's annual exports, according to the UN.

The scathing report follows a year-long investigation, compiled from public hearings with more than 80 victims and witnesses, detailing the "unspeakable atrocities" being committed in North Korea including murder, rape, forced abortions, torture and enslavement.