The wife of a former Malaysian finance minister who has close ties to a political rival of Prime Minister Anwar Ibrahim was charged Tuesday with failing to disclose her assets to anti-graft investigators.

Na'imah Abdul Khalid, the 66-year-old wife of businessman Daim Zainuddin who served as finance minister twice between 1984 and 2001, pleaded not guilty at a court in the capital Kuala Lumpur.

The offence of not disclosing her assets in response to an anti-graft agency request was allegedly committed last November, according to court documents seen by AFP.

Daim, 85, is a close ally of former two-time prime minister Mahathir Mohamad, a fierce critic of Ibrahim, who came to power in 2022 vowing to stamp out high-level corruption.

"No crime was committed by me and I will prove this in court," Na'imah said in a statement outside the court.

"The real crime is the plot to tarnish my husband's reputation. The real crime is the wielding of state power for personal ends and not for the benefit of the people."

She directed a message to Ibrahim, saying "power is brief and there is always a reckoning for those who abuse it".

The court fixed March 22 for the next hearing in the case, where a trial date could be set. If found guilty, she faces a maximum prison term of five years and a hefty fine.

The country's graft agency has said it is investigating Daim. He has called the probe into his affairs a "political witch-hunt". Mahathir has also claimed the investigation is politically motivated.

Last week, the Malaysian Anti-Corruption Commission (MACC) summoned Mahathir's son for questioning over his business activities.

The MACC order to question Mirzan Mahathir is part of its probe following revelations contained in the so-called Panama Papers, "as well as his business activities involving the sale and purchase of government-linked companies", it said in a statement last week.

In August 2022 the MACC said that it had started probing "entities linked and named" in the Pandora and Panama papers, which shone a light on tax evasion by the rich and powerful around the world.

Anwar has been accused of using the MACC investigation to go after his political foes.