Singapore’s banking regulator may take “supervisory action” against DBS Group after the lender’s services faced the worst disruption recently.

MAS assistant managing director Marcus Lim said: “This is a serious disruption and the Monetary Authority of Singapore (MAS) expects DBS to conduct a thorough investigation to identify the root causes and implement the necessary remedial measures. MAS will consider appropriate supervisory actions following the investigation.”

The disruption in the bank’s digital services began on Tuesday and resurfaced on Wednesday.

DBS country head Shee Tse Koon stated that the disruption was caused due to fault in the bank’s access control servers.

“We acknowledge the gravity of the situation and as we work to resolve matters, we seek your patience and understanding,” Shee added.

Shee apologised to customers and assured them that their deposits and monies were safe despite the technical issues.

The lender also has operations in India, Hong Kong and Indonesia, but its biggest retail and wealth management market is at home, where it holds a key position in retail banking.

DBS’ outage comes at a time when several digital-only lenders are making their way into Singapore’s market. DBS itself has invested billions of dollars to upgrade its technology.

Recently, Standard Chartered signed a deal with Singapore’s National Trades Union Congress (NTUC) to launch a digital bank in the city-state.