By Becky Branford
Until now, there has been almost a complete absence of reliable intelligence about who will succeed North Korea's "Dear Leader", Kim Jong-il.
The question has become more pressing amid indications that the 66-year-old has been seriously ill, and in recent days there has been a spate of reports which suggest the question is now being addressed in Pyongyang.
Kim Jong-il, left, "inherited" power from his father Kim Il-sung
But the confusion continues, with the unnamed intelligence sources variously suggesting that the mantle will be passed down to Kim's eldest son, youngest son, or even brother-in-law.
The last succession was settled 20 years before the death of the Great Leader Kim Il-sung in 1994, and publicly announced at a party congress in 1980.
Kim's failure until now clearly to anoint a successor may indicate divisions within the North Korean elite; or it may suggest that the leadership is trying to avoid "lame duck" syndrome, whereby Kim Jong-il's authority is diluted by the emergence of his successor while he remains at the helm.
But the identity of Mr Kim's successor will be key in deciding the future direction of the North Korean state - whether it adopts market reforms and a degree of political openness, or attempts to reassert absolute control over all aspects of the economy and populace.
It will fundamentally affect the durability of the North Korean leadership, say analysts.
Single or collective leadership?
The form of the new leadership is also of interest to observers.
Will a single strongman (it is unlikely to be a woman) emerge, "inheriting" his authority from the Great Leader as did Kim Jong-il? Or will the elite conclude - as some scholars argue - that too many "great" or "dear" leaders end up undermining North Korean ideology, which confers a sun-like centrality on the eternal President Kim Il-sung, and that a collective leadership council is preferable?
There are three centres of power in the North Korean elite: the Kim family, the military and the party leadership.
THE KIM FAMILY
Were there to be another hereditary transfer of power, the obvious contenders would be Kim Jong-il's sons: Kim Jong-nam, 37, Kim Jong-chol, thought to be 27, and Kim Jong-un, about 25.
But such a choice would not be without problems - for one thing, his sons were born to two different women, neither of whom was officially married to Mr Kim.
Eldest son Kim Jong-nam was thought to have embarrassed his father
As the eldest, Jong-nam would be the logical choice. He was thought to have fallen from favour in 2001 when he made an ill-fated attempt to enter Japan on a false passport, but his name has resurfaced in recent reports.
The middle son, Jong-chul, is reported to have accompanied his father on official trips and been the subject of glowing party propaganda - but his name has not come up in the renewed speculation.
Much recent attention has focused on Kim's youngest son, Kim Jong-un, thought to be the favourite of his father. His youth had been seen as problematic, given Korean traditions of seniority.
None of Kim Jong-il's sons has been painstakingly groomed for the leadership in the same way as he was himself. If one of his sons is chosen, he might be more of a figurehead than the real decision-maker.
Mr Kim has daughters, but given the patriarchal nature of Korean society, they are unlikely to be in the running for the leadership.
Since the mid-1990s and the "military-first" policy adopted amid economic crisis and famine, the North Korean military has become elevated within government and society at large.
Many of the possible candidates for the leadership - perhaps a collective leadership - within the North Korean military are in the National Defence Commission (NDC), a body of 10 men, mostly of military rank, at the pinnacle of the North Korean elite.
Leading lights in the N Korean political firmament attended a recent funeral
Jo Myong-rok is first vice chairman of the NDC. He is also Kim Jong-il's second in command in the military - but he is 84 years old and believed to be in poor health.
Gen Hyon Chol-hae, 74, is deputy director of the General Political Department of the KPA (army), and according to one study in past months is thought to be one of Kim Jong-il's most frequent companions. This impression of close proximity to the North Korean leader was underlined by Gen Hyon's presence on the leaders' platform during recent celebrations for the 60th anniversary of North Korea's foundation. During the 1950-53 Korean war, he was Kim Il-sung's bodyguard, so he can also boast a place in North Korea's revolutionary history.
Ri Myong-su, 71, is the director of the administrative department of the NDC. He is said to have close links with Kim Jong-il going back to the 1970s, and to have been one of his most frequent companions in recent years. Both he and Hyon Chol-hae are said to report directly to Kim Jong-il.
O Kuk-ryol was highlighted as a Kim loyalist and rising star by a South Korean intelligence report in 2006. A member of the "1980 group" (rapidly promoted following the 1980 party congress, on the instructions of Kim Il-sung), he is said to have acted as Kim Jong-il's trusted eyes and ears within the armed forces and security apparatus. O later fell from favour, was "purged" but then rehabilitated.
Kim Yong-nam, 80, is head of the North Korean parliament's leadership council and a member of the politburo. He is nominally the country's head of state and ranked second only to Kim Jong-il in leadership lists put together by scholars.
However, according to some commentators, his relatively low profile in North Korean revolutionary mythology makes him an unlikely contender for the top job.
Kim Yong-nam is a leading member of the elite, but unlikely to take sole control
Chang Song-taek, 62, is the husband of Kim Jong-il's sister and until early 2003 was thought to have been one of the Dear Leader's closest confidants. He was once described by high-profile defector Hwang Jong-yop as "the number-two man in North Korea".
In 2003 Mr Chang fell from grace - having reportedly gathered too much influence - and he was "purged" and sent for re-education. But he has now been rehabilitated and brought back to prominence in the administrative department of the Workers' Party - and one recent report suggested he would be the real power behind a leadership nominally headed by one of Kim Jong-il's sons. He also enjoys the advantage of supporters in several key posts, reports say.
According to the Economist Intelligence Unit, Mr Chang may also have pressed the claim of his adopted son, Kim Jang-hyun - in reality a son of Kim Il-sung by one of his nurses, now in his mid-30s.
Other contenders from within the Party structures might include defence minister Kim Il-chol, Choe Thae-bok, or Jon Pyong-ho.