North Korea received no crude oil from China in the whole of 2014, according to recently released official customs data, however experts are sceptical that the numbers tell the whole story.

Historically China has sent more than half a million tons of crude oil a year to the DPRK. The main supply route is from a border facility near Dandong, to what is believed to be North Korea’s only functioning refinery near Sinuiju in the country’s north-west.

However China raised eyebrows last in December 2013 when the shipments disappeared from customs data. According to analysts