North Korea's nuclear test site boss was executed, a Japanese report said, according to Newsweek.
The official, Park In Young, served as the chief of Bureau 131, which supervised the country's military facilities such as the Punggye-ri nuclear test facility and the Sohae Satellite Launching Station.
An unnamed defector told Japanese newspaper Asahi Shimbun that the head of the department was dismissed from his title and then executed by North Korean authorities.
The motive for the alleged execution remains unclear but the source said it was part of a recent "purge" that followed strict disciplinary measures, The Independent noted.
There has been speculation that Park was killed after officials held him accountable for the delay in North Korea's sixth and most powerful nuclear test, which was postponed until September because of delays in tunnel construction.
According to Newsweek, the execution may also be linked to an incident in which 200 people were believed to have been killed when a tunnel collapsed in at the Punggye-ri test site in October.
Experts had cautioned that the site was dangerously close to crumbling after the sixth nuclear blast triggered a 6.3 magnitude earthquake, Fox News said.
News of Park's alleged execution comes days after speculation that another powerful official, General Hwang Pyong So, was executed after he vanished from public, The Sun reported.
The general held a senior military position and served as Vice Marshall after Kim Jong Un but was last seen in October after he was allegedly expelled for taking bribes.
South Korea's intelligence agency said General Hwang Pyong So was punished for "impure" attitudes, Newsweek said.