The investigation into Zhou Yongkang, China's former security chief, will take some time, and the central government is committed to publicizing the result in a timely manner, a senior official said on Wednesday.

Zhou, 71, is by far the highest-profile figure caught up in President Xi Jinping's crackdown on corruption and the highest-ranked official placed under investigation since the nation's reform and opening-up began in 1978.

Zhang Sujun, vice-minister of justice, said at a media briefing that the investigation is still in the hands of the Central Commission for Discipline Inspection - the top anti-graft watchdog - and it will take some time to publicize the decision.