An Argentine resident told a federal court in La Plata that he is Josef Schwammberger, a wanted Nazi war criminal. Shortly after his court appearance, Schwammberger, 75, was hospitalized in the prison medical ward with heart problems. Schwammberger was arrested by federal police Friday in a provincial village. Charges pending since 1973 in West Germany say he was a Nazi SS captain in charge of two Jewish ghettos and a work camp in occupied Poland during World War II. He is wanted in connection with the deaths of 15,000 Jews, according to the Los Angeles-based Simon Wiesenthal Center.