The luxury-loving wife of Malaysia's former prime minister Najib Razak on Wednesday faced a marathon questioning session by investigators probing the multi-billion-dollar scandal that helped topple her husband's government.

Rosmah Mansor, widely reviled in Malaysia due to her profligate spending and imperious manner, arrived at the anti-corruption agency before 10 am (local time) and had still not emerged nine hours later. Local media have reported that officials are wrapping up their probe into Rosmah and her links to the alleged plundering of state fund 1MDB, and she could be charged soon. It was the second time the she has been questioned by the graft-fighting body since her husband Razak's coalition was unexpectedly ousted from office at elections in May after six decades in power.