A Malaysian court threw out more than a dozen money laundering and tax evasion charges on Thursday lodged against the wife of jailed former Malaysian prime minister Najib Razak.

Rosmah Mansor, 73, faced 12 charges of money laundering involving 7.1 million ringgit ($1.6 million) and five charges of failing to declare her income between December 4, 2013, and June 8, 2017.

High Court judge K. Muniandy struck out all 17 charges, saying they lacked "probity, propriety and legality" and ordered a "discharge amounting to an acquittal", according to a copy of the decision seen by AFP.

The Attorney-General's office said it would appeal against the decision, Malaysian media reported.

Rosmah was sentenced to 10 years in jail on separate graft charges in September 2022 but has appealed against that conviction and remains free on bail.

Rosmah has long been criticised by Malaysians for her reported vast collection of designer handbags, clothing and jewellery, acquired on overseas shopping trips.

Her collection of luxury items came under the spotlight after police raids on their family home in 2018 following her husband's election defeat.

It drew unflattering comparisons with former Philippines first lady Imelda Marcos and contributed to accusations that the ousted ruling establishment had lost touch with economically struggling and middle-class Malaysians.

Najib is serving a six-year jail term for corruption related to a massive financial scandal at sovereign wealth fund 1MDB.

He has filed an appeal to serve the rest of his sentence under house arrest and a hearing has been fixed for January 6.

The 1MDB scandal, allegedly involving billions of dollars siphoned from the now-defunct state company, sparked investigations in the United States, Switzerland and Singapore.