Prosecutors named Najib, his wife Rosmah Mansor, his stepson Riza Aziz, and the couple's two other children among 18 respondents in a notice of motion filed at the Kuala Lumpur High Court on Tuesday, Bernama reported.

Najib said the forfeiture action was being used by authorities to delay or avoid returning the assets, which he said were mostly cash belonging to his political party and gifts from various friends and family.

"It is also being used to allow them to continue telling lies and propaganda against me," he said in a Facebook post on Wednesday.

Rosmah's lawyer did not respond to a request for comment on the filing. Legal representatives for Riza and other family members named in the motion were not immediately available for comment.

Since losing a general election in May last year, Najib has been charged with 42 criminal offenses, mostly linked to a multibillion-dollar scandal at 1Malaysia Development Berhad (1MDB), a state fund he founded in 2009.

Authorities have seized cash and luxury goods worth about $275 million from properties linked to Najib, who denies any wrongdoing.

The latest motion concerned cash and assets - including property, vehicles, luxury handbags, watches and shoes - seized from the respondents between May 2018 and March 2019, Bernama reported.

Prosecutors say they were related to alleged money laundering or the result of illegal activities involving the respondents, Bernama said. A date for the forfeiture hearing has not yet been fixed, it added.

Authorities in six countries are investigating alleged money laundering and graft at 1MDB. U.S. prosecutors estimate that about $4.5 billion was misappropriated from 1MDB by high-level officials at the fund and their associates.

According to Bernama, other respondents named in the forfeiture suit include Goh Gaik Ewe, the mother of Low Taek Jho, a Malaysian financier who has been charged in the United States and Malaysia for his alleged central role in the 1MDB case.

Goh and Low's whereabouts are unknown, though Low has consistently denied wrongdoing. A spokesman for Low did not immediately respond to a request for comment on the latest motion.

The suit also named Malaysian Roger Ng, a former Goldman Sachs banker, who has been charged over his role in helping the bank raise bonds totaling $6.5 billion for 1MDB, some of which were allegedly misappropriated.

Last week, Ng was extradited to the United States where he pleaded not guilty to conspiring to launder money and bribe foreign government officials.

Goldman Sachs has consistently denied wrongdoing and said certain members of the former Malaysian government and 1MDB lied to it about how the bond proceeds would be used.

REUTERS