In the first of a series about the worst places in the world for Christian persecution, BBC reporter Stephen Evans finds that Christians in North Korea are tolerated in some areas so long as they do not proselytise by, for example, handing out bibles.

North Korea has topped the Open Doors’ World Watch List of places where Christians face most persecution for the last 13 years. The Pew Research Centre describes its government as “among the most repressive in the world, including toward religion”.

Evans spoke to a former teacher at Pyongyang University of Science and Technology, opened in 2010 and funded and staffed largely by devout Christians from the US and South Korea. “The [perhaps unspoken] deal the regime has made is that it gets a very high-grade teaching establishment and the funders and teachers get an ‘in’ into North Korea for whenever the place is opened up,” his report says.

He also identified four state-sanctioned Christian churches in the capital, Pyongyang. An attendee of one told Evans that it had a congregation of “perhaps 20 people, many of them elderly women”.

North Korea fears Christianity being established as an alternative ideology, Evans says, but it is tolerated so long as it can be controlled – a similar argument made about China by The Guardian.

The latest threat to the state ideology seems to have come from Korean-Canadian pastor, Hyeon Soo Lim, recently charged with committing crimes against the state, despite already having visited over 100 times for humanitarian reasons.

The very public “confession” Lim made last week comes ahead of a humanitarian visit to the state today by South Korea’s former first lady, Lee Hee-Ho. Her visit raises hopes of a thaw in cross-border relations, particularly if she meets North Korean leader, Kim Jong-Un, who has yet to officially receive any South Korean since assuming power three years ago.