TROUBLE is brewing for North Korean leader Kim Jong-un with reports at least 20 senior members of his regime have defected to the Seoul this year.

Among those believed to have fled to South Korea is a high-ranking officer from the People’s Army Politburo who was upset he had been posted to Beijing, the Chosun Ilbo reported.

South Korea’s National Intelligence Service revealed the latest figures to officials last week.

NIS chief Lee Byung-ho said most of the defectors were trusted diplomats who were stationed overseas but now live in South Korea.

Some are believed to be part of the Workers Party notorious Room 39 which manages Kim Jong-un’s ‘slush funds’.

According to the newspaper, one of the officials who defected had been stationed in Africa where he had supervised the bronze monument statutory program.

North Korea is renowned for building huge bronze statues in socialist style and its craftsmen are in demand in countries such as Senegal, Angola and Zimbabwe.

It is believed this diplomat fled with part of the payment for one of the statues.

Another defector is believed to have fled with millions of dollars by using his child’s holiday as an escape.

While members of Room 39 may enjoy a better lifestyle than the average citizen, their families are often held hostage while they are overseas.

According to the NIS, the number of North Korean officials fleeing Pyongyang was steadily increasing.

In 2013 there were reports that eight North Koreans from the country’s elite class defected to Seoul. Last year there were 18.

But analysts believe more actually flee to the US or Europe.

“It is clear that Mr Kim’s rule is becoming increasingly unstable,” Toshimitsu Shigemura, a professor at Tokyo’s Waseda University and an authority on the North Korean leadership, told The Telegraph.

“Defections of senior people first began after the arrest and execution of Jang Song-taek, Mr Kim’s uncle and mentor, in December 2013,” he said. “Many decided to get out simply because they feared they were to be next, and that fear is clearly lingering.”

Prof Shigemura told the newspaper the North Korean military was becoming restless under Mr Kim’s rule.

He cited Pyongyang’s decision to back down from launching an intercontinental missile or to carry out an underground nuclear test earlier this month to mark the 70th anniversary of the founding of the Workers’ Party.

“Mr Kim has purged a lot of people since he came to power – which is not really a surprise as that’s what a Stalinist system is all about – but these defectors must have been certain that they would be executed if they returned home, to leave their families,” he said.

“Alternatively, they might feel that the regime is on its last legs and that they will be able to rescue their families as soon as it collapses.”

The revelations come as a week-long event that reunited North and South Korean families who were torn apart by the Korean War ended.

Around 1,000 relatives from both sides took part in the rare meeting.

However there were tens of thousands who were hoping to get a slot.

It was only the second gathering in five years for those separated by the 1950-53 Korean conflict.

Both sides had agreed to the reunion as part of a deal brokered in August to ease tensions that had pushed them to the brink of armed conflict.

The fact that it went ahead as scheduled had encouraged those who hoped the deal might lessen tension.

But an incident on Saturday threatened to mar the situation.

A South Korean naval vessel fired warning shots at a North Korean patrol boat that had strayed across the border then promptly returned.

But Pyongyang insisted it was a dangerous and deliberate provocation by the South that could “totally derail” the August agreement.

The accord had also envisaged the resumption of official talks between the rival Koreas, but there has been no sign to date of such a dialogue getting under way.

North Korea has rejected repeated requests from the South to make the reunions longer and more frequent and Pyongyang has long manipulated the reunion issue as a tool for extracting concessions from Seoul.