How Western expats live and work in North Korea

An Australian student who lived and worked in North Korea for over a year has been released from detention.

It's not known why Alek Sigley was detained - in his many public writings, the 29-year-old avoided political criticism of North Korea, instead describing the quirks and minutiae of society.

But how did he get there in the first place? And how many expats live in a nation largely sealed off to the world?

Who are the 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 relations improved between the two nations last year, the number of Chinese tourists visiting has surged, says Prof Dean Ouellette from 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 visit each year - and the number of Western residents is even lower.

North Korea researcher Andray Abrahamian, a frequent visitor to the country, estimates there to be only about 200 Westerners in the country.