KUALA LUMPUR/WASHINGTON (Reuters) - Malaysian Prime Minister Najib Razak said on Thursday judgment should be withheld until all the facts are known after the U.S. government filed lawsuits seeking to seize $1 billion in assets bought with money stolen from a state fund he oversaw.

The U.S. Justice Department lawsuits filed in a federal court on Wednesday did not name Najib, instead referring to “Malaysian Official 1.” Some of the allegations against this official were the same as those in a Malaysian investigation into a $681 million transfer to the premier’s personal bank account.

The lawsuits said $681 million from a 2013 bond sale by sovereign wealth fund 1Malaysia Development Berhad (1MDB) was transferred to the account of “Malaysian Official 1”.

A source familiar with the investigation confirmed that “Malaysian Official 1” was Najib.

In Malaysia, the hashtag #MalaysianOfficial1 was trending on Thursday.

The civil lawsuits said that a total of $3.5 billion was misappropriated from 1MDB, a fund Najib established in 2009 and whose advisory board he chaired.

No criminal charges have been filed.

Swiss authorities said on Thursday that, acting on a U.S. request, they had seized three valuable paintings, by Vincent van Gogh and Claude Monet, connected to the 1MDB inquiry. A Swiss Federal Office of Justice spokeswoman said, “The operation is not over yet so we will not comment at the moment on the location of the paintings.”

U.S. prosecutors are seeking to seize $1 billion that they say was diverted from 1MDB into luxury real estate in New York, Beverly Hills and London; valuable paintings; and a private jet.

They also are trying to seize proceeds from the 2013 film “The Wolf of Wall Street”. Riza Aziz, Najib’s stepson and founder of Red Granite Pictures, which produced the movie, was named in the lawsuit.

Red Granite said on Wednesday that none of the funding it received to make the Oscar-nominated film, which took $400 million at the box office worldwide, was illegitimate and nothing the company or Riza did was wrong.

“GOOD GOVERNANCE”

Najib, who has consistently denied any wrongdoing, said on Thursday the U.S. lawsuits were “a civil not a criminal procedure”.

“And we don’t want to come to any conclusions until that process is done,” Najib told reporters at an event in Kuala Lumpur. “We have to establish the facts first. I want to say categorically that we are serious about good governance.”

Najib said the government would give its full cooperation to international investigations of the 1MDB case.

Malaysia’s Attorney-General Mohamed Apandi, however, on Thursday expressed “strong concerns at the insinuations and allegations” of wrongdoing against Najib in the lawsuits.

He said in a statement that none of the probes conducted by law enforcement agencies across the globe over the past year show that any funds were misappropriated from 1MDB.

Apandi said in January the money in Najib’s bank account was a political donation from the Saudi royal family and most of it was returned. Saudi Foreign Minister Adel Al-Jubeir said in April that funds wired into Najib’s personal bank account were a “genuine” donation originating from Saudi Arabia.

Saudi authorities had no immediate comment on the U.S. action.

CLOSER TIES

The lawsuits pose a potentially thorny issue between two countries that have grown closer during the administration of President Barack Obama, who has visited the Southeast Asia country twice in the last two years.

Washington views the moderate Muslim nation as a partner in its fight against radical Islamists, as a member of a U.S.-led Pacific trade group and as part of the U.S. strategic “pivot” to Asia to counter China’s rising ambitions.

Najib, however, said the lawsuits would not affect ties. “This is a separate issue, involving individuals,” he told reporters at the Thursday event.

A top White House official distanced Obama from the Justice Department’s litigation.

“The simple answer is we do not have any control over Justice Department actions,” Ben Rhodes, deputy national security adviser, told Reuters on Wednesday during a visit to Myanmar.

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At home, former premier Mahathir Mohamad led a chorus of opposition voices calling on Najib to step down.

“The time has come where the nation must demand for the removal of the prime minister,” Mahathir said at a news conference, and asked Malaysians to call for a referendum on Najib’s leadership.

Najib has weathered attacks on his leadership since the scandal first broke 18 months ago. He culled dissenting voices from within his ruling United Malay National Organisation (UMNO) and used draconian laws such as the Sedition Act to silence activists and opposition party leaders.

SINGAPORE SEIZES ASSETS

Singapore authorities said in a statement on Thursday they had seized S$240 million ($177 million) of assets in an investigation of 1MDB-related fund flows for possible money laundering.

They also said they found problems at three major banks: top local lender DBS Group Holdings Ltd, the world’s largest private bank UBS AG, and British-based Standard Chartered.

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UBS said on Thursday it had reported some deals it was concerned about and that it is working with authorities investigating banks’ ties to 1MDB. “In this case, UBS self-reported the suspicious transactions and is working closely with regulators to address this matter,” UBS said in a statement.

Singapore’s announcement was the first time authorities there have mentioned 1MDB in statements about their money laundering investigation. In May, they said they were closing down the operations of Swiss private bank BSI AG in Singapore for serious breaches of anti-money laundering rules, the first such action in 32 years. They did not identify 1MDB in that announcement, though Swiss authorities did in a related move against BSI.

The U.S. investigation is the largest set of cases brought by the U.S. Department of Justice’s Kleptocracy Asset Recovery Initiative, which seeks the forfeiture of the proceeds of foreign corruption. The previous largest case in February sought to seize $850 million.

1MDB, set up shortly after Najib came to office, is being investigated for money laundering in at least six countries, including the United States, Singapore and Switzerland.

1MDB said in a statement “it is not a party to the civil suit, does not have any assets in the United States of America, nor has it benefited from the various transactions described in the civil suit”.

GOLDMAN SACHS ARRANGED TRANSACTION

The U.S. lawsuits seek to seize assets “involved in and traceable to an international conspiracy to launder money misappropriated from 1MDB” over a four-year period.

One transaction targeted by prosecutors was a $3-billion bond offering in early 2013 that was arranged by Goldman Sachs International, said U.S. Attorney Eileen Decker at a briefing on Wednesday. She is the chief prosecutor in central California.

More than a third of that money was misappropriated by corrupt officials, she said.

Goldman Sachs has not been accused of any wrongdoing.

“We helped raise money for a sovereign wealth fund that was designed to invest in Malaysia. We had no visibility into whether some of those funds may have been subsequently diverted to other purposes,” a Goldman Sachs spokesman said.

The lawsuits also named Malaysian financier Jho Low and Abu Dhabi government officials Khadem Abdulla Al-Qubaisi and Mohammed Ahmed Badawy Al-Husseiny. Al Qubaisi and Al-Husseiny are former officials at a sovereign fund in Abu Dhabi that participated in deals with 1MDB.

Jho Low did not respond to requests for comment sent to his Hong Kong-based company, Jynwel Capital. Al Qubaisi and Al-Husseiny could not be reached for comment.

Other misappropriated funds from 1MDB were transferred to the co-founder of PetroSaudi, a company that had a joint venture deal with 1MDB, and thereafter to “Malaysian Official 1”, the lawsuits said.