By NICK CUMMING-BRUCE
New York Times
SEPT. 2, 2015

GENEVA — The Swiss authorities said on Wednesday that they had started a criminal investigation of two executives of a Malaysian state investment fund at the center of a corruption scandal that has led to calls for Prime Minister Najib Razak of Malaysia to resign.

The Attorney General’s Office in Switzerland also said it had frozen bank account assets amounting to tens of millions of dollars in relation to the case, but declined to give details.

The office said it was investigating two executives of 1Malaysia Development Berhad, the troubled investment fund also known as 1MDB, and other “person(s) unknown” over a series of offenses, including money laundering, corruption of foreign officials and suspected misconduct in public office.

Investigators are “analyzing and consolidating the evidence,” Anna Wegelin, a spokeswoman for the Attorney General’s Office, said Wednesday.

Ms. Wegelin said the Swiss authorities had begun their investigation on Aug. 14, after receiving two reports of suspicious transactions from the Money Laundering Reporting Office Switzerland — the financial intelligence unit of the Swiss federal police.

The Attorney General’s Office said it had been in touch with the Malaysian authorities, and cooperation with other countries would probably be necessary to establish the facts, she added.

Mr. Najib had set up 1MDB in 2009 to bolster Malaysian economic development, but the fund has faced criticism for lack of transparency over its transactions, which have led to billions of dollars in debt.

Reports that companies linked to 1MDB had transferred close to $700 million into bank accounts believed to be controlled by Mr. Najib have roiled Malaysian politics, leading to calls for him to resign from within his own party and outside it.

Mr. Najib has denied any wrongdoing, and the government’s anticorruption commission has said the money was donated by Middle East interests, although it did not identify the source. No explanation has been given of how the funds have been used.

Tens of thousands of Malaysians rallied in Kuala Lumpur, the Malaysian capital, over the weekend, an event that included a call from Mahathir Mohamad, Malaysia’s longest-serving prime minister and an influential member of Mr. Najib’s party, for a show of people’s power to force him from office.

Malaysia’s police chief, Tan Sri Khalid Abu Bakar, was quoted by local news media on Wednesday as saying that Mr. Mahathir would be questioned over remarks he made at the rally to the effect that members of the governing party had taken bribes.

“There is a corruption crisis here,” José Ugaz, the chairman of Transparency International, a global anticorruption group, told a conference in Kuala Lumpur on Tuesday, observing that Mr. Najib had in recent weeks dismissed an attorney general; arrested or transferred investigators from the anticorruption commission; and taken action against newspapers reporting on the 1MDB issue.

“These are not the actions of a government that is fighting corruption,” Mr. Ugaz said.

The scale of the weekend protests has also drawn the attention of the Moody’s rating agency, which on Tuesday cited the rally as evidence of “political uncertainty that could further undermine market sentiment and capital inflows.”