Data reveals that more than 1,300 North Koreans pleaded for asylum in the UK over a 13-year period, beginning in 2003.
Of these a staggering 505 were refused asylum by the government, while 544 were accepted.
Home Office guidance says that North Koreans fearing persecution back home will likely be rejected because they can claim South Korean citizenship instead.
Yet many defectors fear the consequences for their families back home if they take up residence in the South – which is technically still at war with the North.
Kim Joo-il, an outspoken defector based in London, said: “If you go to South Korea, America or Japan — which are the main enemies for North Korea — then the level of punishment your families will get is much more than if you go to European countries, which are not main enemies.”
Asked what would happen to North Koreans who were refused asylum but wouldn’t go to South Korea, the Home Office refused to comment.
A spokesperson said: “It depends on a case to case basis, and we wouldn’t comment on hypothetical situations.”
North Korea expert Markus Bell, of the University of Sheffield, revealed the figures from the UN High Commissioner for Refugees in a new report.
He said the government struggled to distinguish between defectors arriving via the South, those arriving via another country, and Chinese citizens posing as North Koreans.
Dr Bell said: “We should be employing a more effective means of evaluating who these individuals are, if they have suffered persecution, and where they came from.”
The Home Office says the UN figures do not tally up with its own figures, which show 902 asylum applications from North Korea over the same period.
Of these, 408 were successful, 413 were refused and 77 were withdrawn.
A spokesperson said: “The UK has a proud history of granting asylum to those who need our protection and every case is assessed on its individual merits.”
The UK hosts one of the largest North Korean populations outside of Northeast Asia, with many settling in the London suburb of New Malden.
One of the reasons Britain has been popular with North Korean defectors is it offers their children the prospect of an English-language education.
Mr Kim added: “There is quite a lot of information about the UK in North Korea.
“The UK is [known as] a well developed country and an English-speaking country, so some people choose to come to England.”
While North Koreans are eligible for citizenship in South Korea under its constitution, they are required to prove their nationality and will, in some cases, be refused.
Defectors have complained also of discrimination at schools and workplaces in the South, saying they are treated like “second-class citizens”.