Yak Yew Chee — a top banker at BSI Singapore, a private Switzerland-based bank — whose financial accounts were frozen during an investigation into a Malaysian state-run fund, has quit the bank, according to reports Friday. A former senior vice president at BSI Singapore, Yak is facing a criminal probe in Singapore on money laundering charges associated with 1Malaysia Development Bhd (1MDB), which has been marred by scandal since last July.