North Korea has broadcast images of the once-powerful uncle of leader Kim Jong-un being removed from a meeting, confirming reports of his dismissal.
The dramatic images show Chang Song-thaek being escorted from a party session by uniformed guards.
The state news agency KCNA accused Mr Chang of forming factions against the state, corruption and "depraved" acts such as womanising and drug abuse.
Analysts say such a public dismissal is unique and could signal a wider purge.
It is the biggest upheaval in North Korea's leadership since Mr Kim succeeded his father two years ago. Seen as an economic reformer, Mr Chang handled talks with Pyongyang's only major ally, China.
The KCNA state news agency said the decision was announced after a meeting of the ruling communist Korean Workers' Party Politburo over the weekend.
News of his dismissal filtered out in South Korea last week along with reports that two of his close aides had been executed for corruption. It is unclear when these latest images date from.
The KCNA report accuses Mr Chang of being part of a faction working against the North Korean state.
"Chang pretended to uphold the party and leader but was engrossed in such factional acts as dreaming different dreams and involving himself in double-dealing behind the scenes."
It accused him of offences such as financial mismanagement and selling off national resources for his personal gain, but it also denounced him for leading what it called "a dissolute and depraved life".
"Ideologically sick and extremely idle and easy-going, he used drugs and squandered foreign currency at casinos while he was receiving medical treatment in a foreign country under the care of the party," the KCNA report said.
It added that he had "improper relations" with several women and "was wined and dined at back parlours of deluxe restaurants".
The BBC's Lucy Williamson in Seoul says such an official announcement detailing his alleged crimes is unique.
Almost overnight, Chang Song-thaek has morphed from uncle and mentor to North Korea's young leader, to "anti-revolutionary" criminal outcast, our correspondent reports.
She adds that this could be seen as the latest in a series of carefully calibrated moves to demonstrate Kim Jong-un's control, yet another sign of his authority and an assertion of his independence.
Mr Chang is reported to have been stripped of all his positions and expelled from the party.
On Saturday, North Korean state TV was also reported to have removed footage of Mr Chang from a documentary.
Mr Chang had held senior posts in the ruling party and the National Defence Commission, the North's top military body.
He was seen as a key powerbroker at the time Kim Jong-un took over after Kim Jong-il died in 2011 - he is married to the elder Kim's sister.
He has often been pictured beside Kim Jong-un and was seen by some observers as the power behind the throne.
But despite his family ties to the leadership and senior status, he has been targeted in purges in the past.
In 2004, despite his place in the Kim family, he disappeared from public view.
One report at the time, citing South Korean intelligence, said Mr Chang had been placed under house arrest.
Others suggested he had been sent for "re-education". However, two years later he appeared to have been reinstated.
Kim Jong-il (d)×
Kim Jong-il was one of the most secretive leaders in the world.Tales from dissidents and past aides created an image of an irrational, power-hungry man who allowed his people to starve while he enjoyed dancing girls and cognac.
But a different picture was painted by Sung Hae-rim, the sister of one of his former partners in her memoir, The Wisteria House.
She describes a devoted father and a sensitive, charismatic individual, although she admits even those closest to him were fearful of him.
North Korean media depicted him as a national hero, whose birth to the country's founder, Kim Il-sung, was marked by a double rainbow and a bright star.
The youngest sister of the late Kim Jong-il and the wife of the man formerly regarded as the second most powerful figure in North Korea, Chang Song-thaek.
She has held a wide range of important Workers' Party positions including being a member of the all-powerful Central Committee.
Her promotion to four-star general made Kim Kyung-hee the first North Korean woman ever to achieve such status.
Analysts say Kim Kyung-hee and her husband were seen as mentors for the new leader Kim Jong-un when he came to power in 2011. But news of her husband's execution in December 2013 suggests the most significant upheaval in North Korea's leadership since Mr Kim succeeded his father.
Chang Song-thaek (d)×
Chang Song-thaek was married to Kim Kyung-hee, the younger sister of the late Kim Jong-il. When the inexperienced Kim Jong-un became the new leader in 2011, the couple were widely thought to be acting as his mentors.
In December 2013, the powerful uncle - who sat on the country's top military body - was denounced by the state-run news agency for corruption. Images were shown of him being removed from a Politburo meeting by uniformed guards. He was then executed.
Mr Chang's execution is the biggest upheaval in North Korea's leadership since Mr Kim succeeded his father.
Kim Jong-nam, 39, is Kim Jong-il's eldest son.
Sung Hae-rang, the sister of Kim Jong-nam's deceased mother Sung Hae-rim, has written in her memoir that Kim Jong-il was extremely fond of Kim Jong-nam and was pained to be away from him. Like his half-brothers, Kim Jong-nam studied at an international school in Switzerland.
His chances of succession appeared to be ruined when, in 2001, Japanese officials caught him trying to sneak into Japan using a false passport. He told officials that he was planning to visit Tokyo Disneyland.
Some analysts argued that he may have been forgiven by his father, as there is precedent for the regime reinstating disgraced figures after a period of atonement. Confucian tradition also favours the oldest son.
But in a rare interview while on a trip to China last year, Kim Jong-nam said he had "no interest" in succeeding his father.
Kim Sul-song, 36, is Kim Jong-il's daughter born to his first wife, Kim Young-sook.
Reports say she has worked in the country's propaganda department, with responsibility for literary affairs.
One South Korean report said she had also served as her father's secretary.
Kim Jong-chul, 29, studied at an international school in Switzerland. He works in the WKP propaganda department.
His mother, Ko Yong-hui, is said to have been the North Korean leader's favourite consort.
However, Kenji Fujimoto, the pseudonym of a Japanese sushi chef who spent 13 years cooking for Kim Jong-il, has written that the leader considered his second son "no good because he is like a little girl".
Kim Jong-un, the second son of Kim Jong-il and his late wife Ko Yong-hui, was anointed "the great successor" by Pyongyang.
Like his older brothers, he is thought to have been educated abroad.
A Japanese sushi chef who worked for Kim Jong-il for 13 years up to 2001 said that he "resembled his father in every way, including his physical frame".
Speculation that he was being groomed to succeed his father had been rife for years.
Since taking power, he has presided over a long-range missile test, North Korea's third nuclear test and most recently the execution of his uncle, Chang Song-thaek.
Ri Sol-ju was introduced as Kim Jong-un's wife in state media reports about the opening of an amusement park in July 2012.
Reports simply said he attended the event with his wife, "Comrade Ri Sol-ju".
Little more is known about Ri Sol-Ju, although there has been much speculation about her background since pictures first emerged of Kim Jong-un with an unidentified woman. There is a North Korean singer of the same name, but she is not now thought to be the same person.
State media did not mention when the couple got married.
The grandson of Kim Jong-il and nephew of leader Kim Jong-un has said he wants to "make things better" for the people of his country.
Kim Han-sol, 17, spoke of his dreams of reunification of the two Koreas in an television interview in Bosnia, where he is studying. Kim Han-sol said he had never met his grandfather or uncle.
He described an isolated childhood spent mostly in Macau and China, after his birth in Pyongyang in 1995. In the future, he said he pictured himself going to university and then ''volunteering somewhere''.