North Korean dictator Kim Jong-un is so paranoid he might be poisoned that he orders every leaf of lettuce he eats to be carefully inspected, it has been revealed.

The 'highest authorities' in the secretive country now closely check all vegetables grown in his own farm, '6.17', using a microscope before it ends up on his plate.

A source inside North Korea has revealed the increasingly meticulous process within the Pyongyang farm, amid rumours that Jong-un, 32, is developing a phobia of his greens.

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A source inside North Korea said under order by Jong-un scientists with impeccable credentials spend minutes inspected each lettuce leaf for signs of germs before is reaches the plate of the dictator

North Korean dictator Kim Jong-un (centre) has demanded that the highest authorities in the country closely inspect his vegetables before he eats them (pictured in the Pyongyang Vegetable Science Institute)

'The carefully selected vegetables are examined by their respective units each day before undergoing final inspection', she told Daily NK, based in South Korea.

'Microscopes are used to look for germs, toxins, and other harmful elements.'

She added: 'Instead of just going through farm inspections, the produce needs to go all the way up through the Escort Bureau in order to receive the green light before being presented (to the leader)'.

In addition, only those with suitable 'songbun' - family links and loyalty to the reigning Communist party - are allowed to work on the farm, and have had to study to become doctors before becoming farmhands.

Rumours around Kim Jong-un's diet have swirled for years, amid questions that his growing waistline was due to his 'dangerously high' consumption of imported Emmental cheese which affected his ability to walk

'Inspectors are Pyongyang citizens with immaculate songbun and status who have graduated from Pyongyang Medical University; they’ll spend minutes on one single leaf of lettuce,' the source added.

The farm was built in 1980s for Kim Jong Il, and while processes were in place to check for spies during his rule, they have become much stricter.

Last year it was reported Jong-un had put on weight due to his 'dangerously high' consumption of Emmental cheese, even causing him problems with his ankles meaning he walks with a limp.

And earlier this week he is said to have ordered a 'defeatist' terrapin farm owner to be killed because he was not producing any lobsters.