BUENOS AIRES, Jan. 13 (UPI) -- Argentina has repaid $2.5 billion to the U.S. Treasury, returning funds it received in October under a $20 billion currency swap agreement, authorities from both countries said. Argentina's central bank said in a statement the repayment was completed Friday, using resources from multilateral financial institutions, without naming them. Some analysts said part of the funds may have come from the Bank for International Settlements, based in Basel, Switzerland,