WE CAN'T keep a lid on this," China's disgraced leader Bo Xilai was reportedly told by his police chief when the murder scandal now engulfing Mr Bo's family began to unravel.

With a once-in-a-decade change in leadership months away, the Communist Party's elite must be thinking the same as they confront the first public turmoil at the centre of power in more than 20 years.

Revelations about the former Chongqing party chief issued by the government on Tuesday - above all, that his wife Gu Kailai is suspected of murdering UK businessman Neil Heywood - have upset the carefully staged power succession, turning it into a drama that could claim more victims.

"We're all watching a big drama performed by the top level of the party," said Dai Qing, an investigative writer in Beijing. "Act one is over, and we're waiting to see what happens next."

President Hu Jintao and other leaders now face a quandary - how to prevent rifts even as they manoeuvre for possible gain from Mr Bo's dismissal from the c entral c ommittee and its p olitburo.

That, and especially how it had been handled, has exposed divisions within the ruling elite. Former officials and other sources close to the leadership said these were often ideological, and overlapped with open feuding between left-wing and liberal groups.

Left-wing supporters of the charismatic Mr Bo defended him as the creator of a much-needed new and improved path for China. But those pushing for his fall were alarmed by his sweeping crackdown on organised crime, which brought allegations of widespread abuse of power, and by his nostalgia for Mao Zedong's era.

The differences among the elite carry risks of destabilising the government as the party grapples with mounting pressure on the world's second-biggest economy and waning public confidence.

Signalling the concern that the upheaval could spread, an editorial in the People's Daily admonished officials to close ranks before a congress late this year that will bring in a new elite to replace Mr Hu and his team.

Mr Bo was an abrasive politician whose anticrime campaign and populist vows made other leaders appear unable to meet the public's basic needs.

Ms Dai said that while leaders would remain united for now, most of them were relieved by his removal. But she said broader worries would fester about whether leaders could keep a tight ship while tackling needed economic and political reforms.

"There'll be a smooth 18th p arty c ongress without Bo Xilai. The central leadership has achieved unity for that," she said. "But then we have to see act two. There are certainly still rifts, because each of them (leaders) has his own interests and interest groups to take care of."

The turmoil in the secretive Chinese leadership is the most dramatic since 1989 in the aftermath of the bloody crackdown on democracy protests in Beijing.

Explaining the gulf between Mr Bo's campaign for clean-living socialist virtues, praised by some central leaders and admired by many ordinary citizens, and the allegations about his family's private conduct, will be a challenge for the propaganda machine.

It will be all the more difficult because Mr Bo is a "princeling", the party's equivalent of royal blood because his father, Bo Yibo, served alongside Mao Zedong before and after the revolution.

Before the announcement, officials across China were briefed about the allegations in a series of internal meetings that aired more detailed and damning claims, said sources told about the briefings. The sources declined to be named, citing party rules.

The allegations focus on events leading from Mr Heywood's death to a confrontation between Mr Bo and his then public security chief Wang Lijun in late January. That prompted Mr Bo to strip Mr Wang of his duties, who then fled to the US consulate in Chengdu, about 300km from Chongqing.

Even before their clash, Mr Wang's relationship with his long-time patron, Mr Bo, had soured over months into distrust, said one source who knows both.

According to earlier reports, Mr Wang feared that Mr Bo, keen to preserve his chances for a spot in the next central leadership, would abandon him after central authorities began probing his past, possibly in order to uncover information about Mr Bo.

Mr Wang, apparently seeking to protect himself, gathered information about Mr Bo and his wife, said a separate source. He ordered his men to bug the phones of Chongqing officials and secretly recorded his face-to-face conversations with his boss.

He tried to use the evidence to pressure Mr Bo to support him, but he refused. About a week before his flight to Chengdu, Mr Wang confronted Mr Bo with his suspicions about the death of Heywood, a business consultant who was instrumental in Mr Bo's son attending Harrow, an exclusive private school in England.

"Wang told Bo that four officers refused to sign off on a report about the death, because they suspected it was poisoning," said a source who knows Mr Bo and his family, citing accounts from officials about the case.

"We can't keep a lid on this," Mr Wang told Mr Bo, according to the source, citing the officials. Days later, Mr Bo removed Mr Wang as police chief and, "after Wang Lijun's secretary, driver and the people conducting bugging disappeared, he feared for his life and went to Chengdu", another source said.

Mr Bo and his wife have not been seen in public since his removal was announced on March 15 as Chongqing party chief. At a news conference days before, Mr Bo rejected as "filth" and "nonsense" unspecified allegations on him, his wife, and son, Bo Guagua, who is at Harvard University.

The party leadership must now navigate this minefield of accusations and potential criminal charges in the run-up to its 18th congress, which ushers in a new generation of leaders.

"For the leadership to be doing this, they must really feel they have no choice," said Kerry Brown, head of the Asia programme at UK think-tank Chatham House. "It is incredibly potentially risky and divisive, happens at the worst possible time, and really throws a spanner in the whole works."

The leaders have agreed on ridding the roster of Mr Bo, but they are less likely to find accord on how to move ahead, said a Beijing editor with close links to serving and retired officials.

"In handling this incident, there have been tensions over whether to take a gentler or tougher approach (towards Mr Bo), whether to go slower or faster," said the editor, who spoke on condition of anonymity. "All sides are committed to stability; nobody wants a public rift over this. But the complications will come if, say, Hu tries to take advantage of this incident to take greater control of selecting successors."

One critic of the handling of Mr Bo, a former official who spoke on condition of anonymity, said: "Hu Jintao told everyone not to stir up a fuss, but all this is doing is stirring up a fuss."

In a sign of the party's unease, an insider said it was considering a proposal to delay the opening of the party congress to "shorten the transition period" to the new leaders taking their state posts in March next year. The source spoke on condition of anonymity.

Vice-President Xi Jinping seems virtually certain to succeed Mr Hu as top leader, and Vice-Premier Li Keqiang's rising profile shows he is clear favourite to succeed Wen Jiabao as premier.

But there could be strong disagreement on the rest, said Wu Si, chief editor of Yanhuang Chunqiu (China Through the Ages). "The rules for establishing the new array of power at the top have not been settled. The old rules don't apply and the new ones are a work in progress."