At the time, the U.K. financial regulator said it had already asked two banks named by Lord Hain, HSBC and Standard Chartered PLC, to review possible Gupta-related business. Standard Chartered said it shut down some accounts linked to the Guptas in 2014 after an internal investigation. In a letter sent last week to U.K. Treasury chief Philip Hammond and seen by the Journal, Lord Hain accused HSBC of sanctioning money laundering. He alleged that accounts with U.K.-based HSBC in Dubai and Hong Kong were used for Gupta money transfers out of South Africa.