North Korean state media reports that army head Ri Yong-ho has been relieved of his political positions.
As well as being head of the pariah State's huge army, Ri was vice-chairman of the powerful Central Military Commission and held top posts in the ruling Workers' Party.
North Korean media reported that he was given leave due to illness.
However, some speculate that the move may suggest that new leader Kim Jong-un and his closest advisors may be purging the ruling elite to tighten their own grip on power.
He showed no signs of ill-health when he was seen in public last week with Kim Jong-un and senior military officials on a visit to a memorial in Pyongyang.
Ri was a close political ally of Kim Jong-un's father, former leader Kim Jong-il.
It was not clear from the report whether Ri, a career military man who held the rank of vice-marshal, was also relieved of his posts in the the world's fourth largest army.
Sarah Sheffer, Reuters