N Korea images show aide's removal

The North Korean leader Kim Jong-un has overseen the ousting of his previously powerful uncle Jang Song-thaek for crimes including faction-building and "dissolute and depraved" behaviour involving drug use, womanising and gambling, North Korean media has announced.

North Korea has dismissed Jang Song-thaek, the once powerful uncle of leader Kim Jong-un, for what it described as a string of criminal acts including corruption, womanising and drug-taking.

South Korea's spy agency last week said it believed Jang, long regarded as the second most powerful man in the secretive state, had been relieved of his posts in November.

The sacking on Monday means Pyongyang is undergoing its biggest leadership upheaval since the death in 2011 of former leader Kim Jong-il, the younger Kim's father.

Jang is married to Kim's aunt, the daughter of the North's founding leader Kim Il-sung, and was widely considered to be working to ensure his nephew firmly established his grip on power in the past two years.

Last week a South Korean official said Jang was likely alive and in no immediate physical danger, as was his wife, Kim Kyong-hui.

Experts say Jang's removal will help the younger Kim consolidate his power base with a group of younger aides.

Jang had been a prominent fixture in many of the reports and photographs of Kim Jong-un's public activities, but his appearances have tapered off sharply this year and he has not been since in official media since early November.