Egyptian tycoon Naguib Sawiris has enjoyed unprecedented access to North Korea’s secretive leadership since signing a deal to build North Korea’s first commercial mobile phone network.

He has been a regular visitor to Pyongyang in recent years and, in 2011, he was photographed holding the hand of the late Kim Jong Il and linking arms with the North Korean dictator’s brother-in-law Jang Song Thaek.

Since...