Two Goldman Sachs bankers concocted a scheme involving their wives to conceal kickbacks they received for helping to loot the 1MDB sovereign wealth fund, one of the bankers testified on Thursday at the corruption trial of the other, Roger Ng.

Tim Leissner, who had been Ng's supervisor at Goldman before becoming the star government witness against him, said he received kickback payments from a Malaysian intermediary, Jho Low, for helping embezzle funds Goldman raised for...