Former managing director of Swiss bank BSI Yak Yew Chee has been sentenced to an 18-week jail term and a fine of S$24,000 (approximately RM75,000) after pleading guilty to four criminal charges.

Yak, who used to be a bank relationship manager for businessman Low Taek Jho, pleaded guilty for forgery and failure to flag suspicious transactions in the investigations related to 1MDB.

He was also the banker in charge of the 1MDB account for BSI.

Yak, in October, was slapped with seven criminal charges in connection with Singapore's probe into 1MDB.

Singapore’s Straits Times reported that the other three charges were being stood down for consideration in sentencing.

Apart from Yak, another former BSI banker, Yeo Jiawei is also facing trial for four counts of witness tampering.

In his mitigation plea, Yak's lawyer Lee Teck Leng said his client was “truly remorseful”, and had cooperated with the Commercial Affairs Department in its investigations.

Lee added that Yak had committed the crimes at the behest of Low, who “was not just my client's biggest customer, but was in fact BSI's biggest customer”.

Due to Low's connections, other entities also became clients of BSI, Lee said.

Low was confirmed as a "person of interest" in the Singapore police’s probe into an alleged multibillion-dollar money-laundering scheme.

Considered as the mastermind in the financial movements around 1MDB, Low, however, has denied any wrongdoing.