An Australian student who lived and worked in North Korea for over a year has been released from detention.
It is not known why Alek Sigley was detained ̵
But how did he get into the first place? And how many expats live in a nation virtually sealed to the world?
Who are foreigners in North Korea?
Broadly they can be divided into two groups: Westerners and Chinese.
China is North Korea's strongest and closest ally, and since the relationship has improved between the two nations last year, the number of Chinese tourists visiting has increased, said Prof Dean Ouellette of Kyungnam University in South Korea.
He estimates that up to 120,000 Chinese tourists visited in the past year. In contrast, fewer than 5,000 Western tourists each year – and the number of Western residents is even lower.
North Korean researcher Andray Abrahamian, a frequent visitor to the country, estimates to be only about 200 Westerners in the country.
Almost everyone is based in the capital, Pyongyang, and is tied to a handful of diplomatic missions, humanitarian aid, or affiliated universities – including Pyongyang University of Science and Technology, which has an exchange program for teachers.
Is it hard to get in?
Most Western residents living in North Korea are in "rather specialized conditions", says Dr. John Nilsson-Wright, an international relations expert from Cambridge University and Chatham House. 19659007] "It is relatively unusual for people to spend a very long episode of time in North Korea, they are usually with a kind of government program for a specific time, and numbers are quite small," he tells the BBC.
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Outside these areas it can be very difficult to gain access to a NGO employee's visa. Organizations must secure a North Korean partner or sponsor who can guarantee them, says Prof Ouellette.
"The investigation process would be more thorough and probably involves the Ministry of State Security for anyone trying a long-term stay," he says.
What about Alek Sigley?
Aleke first visited North Korea on a tourist visa in 2012 before setting up his own travel agency.
He continued to lead dozens of trips to the state and built up the networks he needed to study at Kim Il-sung University, the nation's top university.
"There is no open application process and being accepted is often conditional on having contacts in the country," he wrote in a blog post.
"I had made some friends who were willing to stand up for me and help me apply even though I reached the finish line still took two years of email exchanges, a personal statement, a medical examination and a police certificate confirming that I didn't had a criminal record. "
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In April, he began his two-year master's degree in Korean literature. He noted that he was one of three Western students at his university – the other two men are from Canada and Sweden.
According to Chinese state media, the Chinese government each year offers 60 students full scholarships to North Korean universities. About 70 other Chinese students pay their own way there.
So what is it like to live there?
In his blogs, Sigley wrote about the freedom he had in relation to tourists who have to adhere to their guidance and only visit designated areas.
"As a long-term foreign citizen on a student visa, I almost without access to Pyongyang," he wrote. "I'm free to walk around town without anyone accompanying me."
But Mr Abrahamian himself says as residents, Westerners often cannot access "many places – restaurants and buildings and neighborhoods "- partly because they lack things like the state-issued symbol to pay at a restaurant.
They also have to live their lives within a set of sensitive rules. Mixing with the locals is frowned upon. Public photography is risky.
"You can never take anything for granted when you are there," says Prof Nilsson-Wright.
He refers to the case of American students Otto Warmbier, who was imprisoned in North Korea in 2016 for 17 months after being accused of stealing a propaganda sign during a five-day trip.
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He died just days after he was returned to the United States in coma. After that, the United States banned its citizens from visiting the state.
"As you can see with the Warmbier case, well-meaning Westerners can break into local regulations in a way that can be serious and sometimes fatal," said Prof Nilsson-Wright.
Most Western expatriates are well aware of the risk, says Mr Abrahamian.
"[But] as hard as it is worth trying to establish relationships with society," he says. "We believe that contact is the best way to reduce suspicions and open the country."