(July 10): Swiss prosecutors are now investigating six people for alleged involvement in Malaysia’s multi-billion dollar 1MDB scandal, days after former Malaysian Prime Minister Najib Razak was charged with corruption for his role in the affair.

Two Swiss banks -- Falcon Private Bank and BSI SA -- are also suspected to be involved, Swiss Attorney General Michael Lauber told reporters Tuesday in Putrajaya following a meeting with his Malaysian counterpart, Tommy Thomas.

Switzerland has been investigating how billions of dollars earmarked for economic development through 1Malaysia Development Bhd. was diverted and made its way into Swiss banks for the personal enrichment of the accused. Lauber, working with Singaporean and US authorities, had been publicly critical in the past of Malaysian authorities for their lack of cooperation. After Najib lost his bid for re-election in mid-May to rival and former premier Mahathir Mohamad, the new government said it would reopen a graft probe.

“After the latest developments in Malaysia,” the Swiss A-G’s office “was very much interested in renewing dialogue with the competent authorities in Malaysia,” it said in a statement Tuesday.

Swiss prosecutors earlier in May revealed they’d opened criminal proceedings into two former officials of PetroSaudi. Under the pretense of investing about US$1 billion ($1.36 billion) in a joint venture between 1MDB and PetroSaudi, 1MDB officials and others instead transferred about US$700 million to an account not associated with PetroSaudi, the US Justice Department alleged in a 2016 seizure order.

Lawyers for PetroSaudi deny any wrongdoing. Najib, the former prime minister, has pleaded not guilty to the charges against him and was released on US$247,000 bail. Spokespeople for EFG and Falcon Bank declined to comment.

Word of both banks’ involvement is not new and they have already faced punishment. Zurich-based Falcon and BSI, since bought by larger rival EFG International AG, were ordered in 2016 to shut down their Singapore banking units for facilitating illicit payments. BSI was fined 95 million Swiss francs ($130.1 million) last year for ignoring “clear warning signals.” Falcon, owned by Abu Dhabi investors, is still the subject of a criminal investigation by Swiss federal prosecutors.

Coutts & Co., sold by Royal Bank of Scotland Group Plc in 2016, was fined US$6.5 million in 2017 for allowing US$2.4 billion worth of assets related to the Malaysian development fund to flow through its accounts in Switzerland.