The onus is on Najib to convince the world of his innocence

Malaysia's prime minister, Najib Razak, has repeatedly denied wrongdoing over the state sovereign fund 1MDB's huge debts. He claims opponents are trying to orchestrate his removal through allegations that almost US$700 million was transferred into his bank accounts. Yet his explanations have not been convincing. The dismissal of critics in his cabinet, the disarray surrounding an official inquiry and the silencing of media have only heightened speculation. Restoring lost moral authority requires ensuring a genuinely independent investigation.

There is every reason why this has to happen. The 1MDB scandal has damaged Malaysia's image and outlook, causing the stock market and the ringgit currency to plummet. Malaysia's oil-driven economy was already in trouble over the sharp fall in prices. Allegations of corruption shrouding the leadership only deepens the crisis.

Najib's replacement of five ministers including his deputy, Muhyiddin Yassin, and the attorney-general, Abdul Gani Patail, has caused ructions in the United National Malays Organisation, the dominant partner in the Barisan Nasional coalition. Muhyiddin, critical of the government's handling of the scandal, was removed in favour of the prime minister's strongest ally, Home Affairs Minister Ahmad Zahid Hamidi. Patail was just three months from retirement and the leader of the special task force investigating 1MDB. The chair of the parliamentary committee looking into the allegations, Nur Jazlan Mohamed, was promoted to the cabinet and his posting will mean a suspension of its work until October. The moves come amid a media crackdown, with websites blocked and two publications belonging to The Edge group suspended.

Replacements and suspensions buy time, but do not resolve the crisis. Najib's strongest critic, former prime minister Mahathir Mohamad, continues to call for him to resign. Rumours remain rife. If Najib has done nothing wrong, he has to do a better job of proving his neutrality.