An Open Doors eyewitness has confirmed widespread reports of the effects lack of food is having on children's growth in North Korea.

North Korea is intolerant of religion and many Christians are interned in labour camps where conditions are extremely harsh.

The economy has been badly damaged by years of mismanagement and international sanctions aimed at putting pressure on the country over its nuclear ambitions.

The Open Doors souce said: 'Not too long ago I met a North Korean refugee family in China. Their children were the ages of my children at the time – nine and six – or so it seemed. I couldn't have been more wrong. They were 14 and nine. But their growth was stunted because they had been malnourished their entire lives.'

The North Korean state determines what food rations its citizens will receive. Another source inside North Korea told Open Doors: 'Recently, North Korean citizens were asked to donate money towards several construction projects. In the meantime, often we don't get any food rations, even though we're at the end of the winter, which always means that there are a lot of food shortages. The situation of the powerless North Korean citizens is getting worse.'

The North Korean government itself announced recently that daily rations would have to be cut from 550 to 300 grammes.

According to the UN, North Korean food production in 2018 fell to its lowest level for over a decade, and an estimated 11 million North Koreans – nearly 44 per cent of the population – are undernourished. 'Widespread under-nutrition threatens an entire generation of children,' said Tapan Mishra, the UN resident coordinator in North Korea.

During the 1990s, the great famine in North Korea forced many to risk the perilous trip across the border in search of food. Many North Koreans defected in search of a new life. The number of people who starved to death in the famine is not known; estimates vary between 240,000 and 3,500,000.

Studies comparing the height of North Koreans and South Koreans have shown that their growth was seriously affected by this famine. German researcher Daniel Schweendiek analysed 2002 data and found that pre-school children in North Korea were up to five inches shorter than their South Korean contemporaries. Other studies of young adults who would have been affected by lack of food during their growing years put the difference at between 2-4 inches for men and 1.6-2.5 inches for women.

An Open Doors expert said: 'From a region we cannot disclose we received a report that the prices of food products continue to rise. A large portion of the harvest goes directly to the government and what remains is too little for most people to survive.' A kilo of rice costs more than twice the average monthly salary of a North Korean.

Open Doors workers smuggle in enough food to keep 60,000 secret Christians alive in North Korea. They also smuggle in much-needed medicines, along with Bibles and Christian literature.

North Korea remains number one on the Open Doors World Watch List, as it has done every year since 2002. Anyone who dares to believe in a higher authority than the Kim family is considered an enemy of the state. Open Doors estimates that there are between 200,000 and 400,000 secret Christians in North Korea. Of those, between 50,000 and 70,000 Christians are imprisoned in labour camps.