An official inquiry in Malaysia claims a tycoon and a former government minister were involved in a covert campaign to influence judicial appointments seven years ago.

The inquiry is seen as the boldest move yet by the government to clean up the judiciary, which has been under a cloud since 1988 over its independence and integrity.

The government has ordered its chief prosecutor to investigate the two, a lawyer as well as a retired chief judge and former premier Mahathir Mohamad, whom the inquiry says was also "entangled" in the process.

Once regarded as one of the more independent institutions in Malaysia, the judiciary has lost credibility since Mr Mahathir clashed with top judges, three of whom were removed in 1988.

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