Kevin Swampillai, who worked for BSI Bank Singapore from 2010 to 2016, said that bank’s clients such as 1MDB and its then subsidiary, SRC International Sdn Bhd, had wanted to utilise his bank’s “fiduciary funds” service.

He said customers usually used the service to “facilitate the flow of money to a particular destination, while also obscuring the identity of an investor”.

Swampillai said the service gave the bank’s clients “limitless flexibility” to structure transactions and determine which banking instruments to use “to optically legalise the flow of money”.

“The client is in control of the timing and amounts channelled through such fiduciary structures,” he said.

He said he concluded that Najib was “aware” of the transactions because they involved large funds and needed “apex approval” from a “highly placed government official such as the prime minister”.

Swampillai also said he met Low Taek Jho, or Jho Low, some time in 2011 with his then colleagues, Yeo Jiawei and Yak Yew Chee, after the fugitive businessman inquired about BSI’s fiduciary funds service.

“Jho Low indicated to us that he was Najib’s adviser,” he said.

Shortly after the meeting, SRC, 1MDB, and 1MDB Global Investment Limited began using BSI’s fiduciary funds service, he said.

He said he did not suspect that the companies involved were owned by MoF Inc until news reports on Low emerged in 2015.

Low used the service because it gave the “optical illusion” that funds belonging to SRC and 1MDB were placed in bona fide investments, he said.

“(The service used by SRC and 1MDB) included conduits to channel monies to various beneficiaries known only to the (bank’s) clients.

“At the same time, it was aimed at obscuring the clients’ intentions from scrutiny,” he said.

Najib is facing 25 counts of money laundering and abuse of power over alleged 1MDB funds amounting to RM2.28 billion deposited into his AmBank accounts between February 2011 and December 2014.

The hearing before Justice Collin Lawrence Sequerah continues.