U.S. prosecutors are preparing to bring criminal charges against two former employees of Standard Chartered PLC for alleged breach of Iranian sanctions, the Financial Times reported, citing people briefed on the matter.

The possible charges center on alleged breaches involving companies with links to Iran, they said. This comes a week after it was reported that U.S. authorities may impose a $1.5 billion penalty on Standard Chartered for allegedly allowing customers to violate Iranian sanctions at least five years ago.

U.S. investigators have focused on how the bank continued to process transactions in U.S. dollars for entities controlled from Iran, even after it agreed to pay $667 million in fines for carrying out similar activities in 2012.

The U.K.-headquartered group is yet to respond to preliminary findings received from the U.S. Justice Department, the Manhattan District Attorney and the New York Department of Financial Services, among other regulators and agencies, a person briefed on the talks told the FT.