Is North Korea hiding a bigger problem behind its Covid-19 outbreak?

Choi Jung-hun smiled as I read out the latest official Covid-19 figures from North Korean state media: fewer than 5 million cases of "fever" and just 73 fatalities -- a fraction of the death toll of every other country in the world.

"North Koreans call them rubber band statistics," he said, in a nod toward Pyongyang's flexibility with the truth. "It's hard even for North Korea to know its own numbers."

He speaks with some authority. Choi was a doctor for more than 10 years in North Korea, specializing in infectious diseases before he fled his home country in 2011.