The United States Justice Department named three individuals yesterday (Wednesday July 20), including the stepson of Malaysian Prime Minister Najib Razak, in a civil-forfeiture suit against more than US$1 billion (S$1.36 billion) in assets bought with money believed to be stolen from funds directly linked to state-owned 1Malaysia Development Berhad (1MDB).

The three were Mr Riza Aziz, the stepson of Datuk Seri Najib; Malaysian financier Jho Low, a confidant of the Malaysian Premier; and Mr Mohamed Badawy al-Husseiny, a former official at a government fund in Abu Dhabi, United Arab Emirates, that participated in deals with Malaysia's fund.

Prosecutors also named a fourth person in the case, former Abu Dhabi government representative Khadem Al Qubaisi.

The sensational case is shaping up as the largest asset recovery initiative by the US government.

The move by the US government is set to renew pressure on the embattled Najib administration that has struggled to put a lid on the shockwaves from the 1MDB scandal over the past one year. The scandal has resulted in the sacking of former deputy prime minister Muhyiddin Yassin, former attorney-general Abdul Gani Patail and other senior government official opposed to his administration.

The legal suit is also expected to add momentum to other international probes, including investigations in Singapore, into the financial dealings of 1MDB.

Financial executives familiar with the ongoing investigations say assets that were acquired by individuals involved in the scandal in other jurisdictions could come under scrutiny.

The complaint does not name Mr Najib, but it does cite "Malaysian Official 1", described as a high-ranking government official who oversaw the fund and is a close relative of Mr Aziz, The New York Times said.

1MDB was overseen by Mr Najib as head of its advisory board.

The US suit alleges that over US$3.5 billion was misappropriated by unidentified Malaysians in transactions over several years using sham corporate vehicles and shell companies to divert funds for personal gain.

1MDB officials in Kuala Lumpur did not respond to requests for comment.

Mr Riza partly owns Red Granite Pictures, a Hollywood production company that backed The Wolf Of Wall Street. 1MDB in April said it had "never invested in nor transferred funds to Red Granite Pictures, whether directly or via intermediaries", and has denied wrongdoing more broadly over its finances, Bloomberg reported.

Mr Low has said he provided consulting to 1MDB that did not break any laws.

The US government is seeking, among others, assets such as royalties from The Wolf Of Wall Street, homes in Beverly Hills, California, and a penthouse in the Time Warner building in Manhattan, according to the filing.

These total more than US$1 billion, the Justice Department said.

1MDB was set up to pursue investment and development projects for Malaysia.

"However, over the course of an approximately four-year period, between approximately 2009 and at least 2013, multiple individuals, including public officials and their associates, conspired to fraudulently divert billions of dollars from 1MDB through various means," the Justice Department said in court filings.