Kim Jong Un has ousted the uncle who served as one of his closest aides, according to South Korean intelligence, marking the most significant casualty in a sweeping purge of the country’s top ranks during the young North Korean leader’s two years in power.

As vice-chairman of the National Defence Commission, and brother-in-law to the late Kim Jong Il, Jang Song Thaek was seen as one of the two most influential members of Mr Kim’s administration. But he has been dismissed from his official positions, South Korea’s National Intelligence Service claimed yesterday. It said that this had been announced to the North Korean military, and that two of Mr Jang’s close associates had been executed publicly.

Since succeeding his father in December 2011, Mr Kim has undertaken the most thorough purge of his senior officials since the late 1950s, according to Andrei Lankov at Kookmin University.