Department 54 supplies electricity, coal, fuel, clothes and other necessities to the military. It used to be under direct army control but was moved to the National Defense Commission after Jang became its vice chairman and entrusted his confidant Jang Su-gil with running it.

The ouster of North Korean eminence grise Jang Song-taek seems to have been triggered by rampant corruption in a state agency tasked with feeding and clothing the Stalinist country's million-strong army.

According to sources, the problem started when leader Kim Jong-un toured several military units and promised to solve their shortages of daily necessities. Kim ordered Department 54 to deal with the matter, but the department failed to comply.

Kim then instructed officials to probe the department and apparently discovered that Jang's orders had been prioritized over his. The probe took place in early October of this year, leading to the arrests and public executions of Jang's cronies Ri Yong-ha and Jang Su-gil. Jang was arrested on Sunday.

Department 54 has burgeoned well beyond a military supplier and now owns department stores in Pyongyang and Wonsan as well as controlling mines, power plants, cement factories and agricultural distribution networks throughout North Korea.

When the North faced a food shortage in 2011, Department 54 imported 50,000 tons of corn and distributed it to military units around Pyongyang and the residents of the capital.

Sources said Department 54 officials were also implicated in corruption in the running of a chain of restaurants overseas under the name Haedanghwa.

Democratic Party lawmaker Hong Ik-pyo cited a source in China as saying that Department 54 was warned several times by the No rth Korean Cabinet against corruption in the Haedanghwa chain, triggering an investigation that eventually led to Jang.

Meanwhile, sources said the purge of Jang and his cronies was spearheaded by Kim Jong-un's half-sister Kim Sul-song and her husband Sin Bok-nam, who presently lead efforts to reform the Workers Party.

