An investigation into wealthy financier R. Allen Stanford’s operations is intensifying, with the FBI looking into his financial group in the U.S. and regulators in Antigua scheduled to visit his bank there. Stanford Financial Group Co., which has more than 30,000 investors, has been recently advising clients that they can’t redeem their CDs for two months, a person familiar with the matter said. A spokesman for Stanford Financial said depositors may withdraw funds in accordance with the terms of their accounts.