China's top disciplinary official said the case against disgraced politician Bo Xilai has been "relentlessly pursued" as he vowed to root out corruption, state media reported on Tuesday.

The comments by He Guoqiang, a member of the nine-man Communist Party committee that runs China, signalled the party would take a hard line on Bo and China's graft problem at an important political meeting next month.

"We have resolutely placed the investigation of cases as the main priority of our work and maintained strong momentum to punish corruption," Xinhua quoted He as saying.

"Corrupt individuals, no matter who they are, will be followed relentlessly and will never escape punishment."

He, who heads a powerful Communist Party commission that oversees disciplinary matters, acknowledged public anger over corruption but said that building a clean government would be a long-term task.

Bo, once a rising political star, was expelled from the ruling Communist Party last month for a series of alleged crimes and corrupt activities. His wife was given a suspended death sentence in August for murdering a British businessman.

The scandal has been a deep embarrassment to the party just as it was aiming for a smooth build-up to a party congress that is held every five years and will open on November 8.

The congress will signal the start of a once-a-decade leadership change that will see President Hu Jintao and other top leaders begin stepping down from their posts.

He said 660,000 Communist officials were punished by the party for corruption over the past five years, while 24,000 officials were criminally tried for graft during the same period.

He added that the case of Bo, the former party boss of the huge southwestern city of Chongqing, and other major graft cases, were "relentlessly pursued".

On September 28, China ended months of speculation over how it would handle Bo's case by announcing he had been dismissed from the party, and would be prosecuted for abuse of power, taking bribes, improper sexual relations, and other offences.

No date has been announced for a trial.

Bo, the son of a Communist revolutionary hero, had once been widely tipped for promotion to the party's top echelons.

China's leaders have repeatedly declared official corruption and abuse of power as a threat to the legitimacy of their rule. They have announced numerous graft crackdowns but the problem remains deeply entrenched.