Traffic passes a 1Malaysia Development Bhd (1MDB) billboard at the Tun Razak Exchange development in Kuala Lumpur, July 6, 2015. REUTERS/Olivia Harris

Singapore officials on Monday charged two former employees of BSI Singapore, a private Switzerland-based bank, in a case linked to the scandal-hit Malaysian state fund 1Malaysia Development Berhad. Authorities accused Yak Yew Chee and Yvonne Seah Yew Foong of failing to reveal suspicious transactions involving Malaysian prime minister’s aide Jho Low.

Yak, who was a senior vice president at BSI, and Yvonne, who was Yak’s former subordinate, face seven charges including forgery, according to court papers filed Monday. The two did not enter any pleas and were released after posting bail of $25,500 each.

Low, whose assets have been seized by officials in Singapore as part of the probe, was one of Yak’s clients. According to court documents, Yak “fraudulently” signed letters addressed to BNP Paribas Switzerland, Kendris Ltd and Rothschild Trust AG Switzerland citing Low as a client at both BSI Singapore and BSI Switzerland.

Yak allegedly had reasonable grounds to believe that $110 million transferred by Low “directly represented proceeds of an act that may constitute criminal conduct” and he did not disclose the suspicion to officials.

In an August court filing, the U.S. Justice Department said it is seeking to seize more than $1 billion of assets linked to 1MDB, including 11 luxury properties in the U.S. The department said that 1MDB’s misappropriated funds made their way through shell companies, checks, wire transfers and accounts with Deutsche Bank AG, JPMorgan Chase & Co., Rothschild Bank AG and BSI Bank Ltd. Those banks were not accused of misconduct.

Malaysian Prime Minister Najib Razak had set up 1MDB to boost the country's economic growth. Investigators reportedly believe that over $1 billion from the state-run fund can be traced to Najib’s private bank accounts. He has denied any wrongdoing.