KUALA LUMPUR • A detained Malaysian lawyer has gone on a hunger strike after being arrested over his involvement in efforts to expose a scandal rocking Prime Minister Najib Razak's government.

Mr Matthias Chang was arrested on Thursday under a tough domestic security law that allows detention for up to a month without trial.

Mr Chang had been representing Mr Khairuddin Abu Hassan, a former Umno member who was detained last month under the same security law, after he launched a global campaign to highlight alleged graft involving Datuk Seri Najib and state-owned firm 1Malaysia Development Bhd (1MDB).

Both men are being held under the Security Offences (Special Measures) Act, a 2012 law that replaced the Internal Security Act.

Mr Chang released a statement calling his and Mr Khairuddin's arrests "a heinous tactic" to silence those speaking out "against the tyranny and corruption of the Najib regime", and announced he had begun refusing food.

Mr Najib faces mounting calls to explain massive sums of money allegedly missing from 1MDB, of which he is chief adviser, as well as the sensational revelation in July that nearly US$700 million (S$980 million) in mysterious transfers had been made to his personal bank accounts.

AGENCE FRANCE-PRESSE