One of the highest-ranking North Korean diplomats to defect in decades has penned a tell-all memoir about his experiences inside the regime’s inner circles, claiming that top official Jang Song Thaek was burned alive and revealing the existence of a secret organization managing leader Kim Jong Un’s slush fund.

Ryu Hyun-woo, the DPRK’s former acting ambassador to Kuwait, writes in “Kim Jong Un’s Secret Vault” that the North Korean leader ordered the execution of Jang by fire in 2013, insisting that he didn’t deserve a burial.

He also recounts high-level discussions about the American captive Otto Warmbier, stating