TEMPO.CO, Kuala Lumpur - Malaysia has issued an arrest warrant for financier Low Taek Jho, wanted for questioning in a graft probe involving former prime minister Najib Razak and state fund 1MDB, a source familiar with the matter said.

Jho Low, as he is popularly known, was regarded as close to Najib and his family and is seen as a central figure in the 1MDB scandal, which is the subject of multi-billion-dollar money laundering investigations underway in Malaysia and around the world.

The Malaysian Anti-Corruption Commission (MACC) issued a warrant for Jho Low, along with Nik Faisal Ariff Kamil, a director of SRC International, a former unit of 1Malaysia Development Berhad (1MDB), the source said.

The authorities are also preparing warrants for Roger Ng, a former Goldman Sachs Group Inc banker, and 1MDB's ex-chief, Shahrol Halmi, the source said.

The source said anti-graft investigators are reaching out to Low's lawyers to seek his return to Malaysia to give a statement.

"We know roughly where he is and efforts are being made to reach out to authorities in the countries where we believe he may be," the source said, declining to be identified due to the sensitivity of the matter.

Read: Najibs Wife Questioned by Malaysia Anti-graft Agency

The news was first reported by Bloomberg on Thursday, citing people familiar with the matter.

The anti-graft agency, a lawyer for Low and Shahrol did not immediately respond to requests for comment. Reuters was unable to reach Ng and Nik Faisal immediately.

Bloomberg said the four individuals had not been charged with wrongdoing, and it was not clear what suspicions underpinned the warrants.

1MDB is the subject of money-laundering probes in at least six countries, including the United States, Switzerland and Singapore.

The U.S. Department of Justice has alleged that more than $4.5 billion was misappropriated from 1MDB, and about $700 million of that went to Najib's personal bank accounts.

Najib, who founded 1MDB in 2009, has consistently denied wrongdoing.

Low advised on investments and negotiated deals for 1MDB, though he never held any official role in the fund.

On Thursday, MACC issued a notice for Low and Nik Faisal to contact the commission immediately to help in its investigation. Low, through his lawyers, said he would cooperate.

Empowered by a new government elected last month, the agency has relaunched a probe into why $10.6 million from SRC was transferred into Najib's bank account.

Anti-graft agents have questioned both Najib and his wife, Rosmah Mansor, following his shock election defeat last month to former mentor-turned-foe Mahathir Mohamad.

Read: Malaysia Police Say Found $28.6 mn in 1MDB-linked Raids

Goldman Sachs had helped 1MDB raise $6.5 billion in three bond sales in 2012 and 2013 to invest in energy projects and real estate to boost the Malaysian economy.

Instead, more than $2.5 billion raised from those bonds was misappropriated and used to buy artwork, luxury properties in New York and London and to pay off gambling debts in Las Vegas, the U.S. Justice Department has alleged.

The bank said in November it had received requests from "various government bodies" and was cooperating, Bloomberg said.

REUTERS