The Department of Homeland Security adamantly denied Wednesday that its officials had interrogated a senior at the University of Massachusetts at Dartmouth because he tried to borrow from acampus library an unabridged version of The Little Red Book. The alleged incident has prompted a controversy, but Jamie Zuieback, a spokeswoman for the department, said, “We investigate violations of the law, not individuals’ reading habits.” She said that department officials have “serious questions about the veracity of the claims” made by the student. She also indicated that the department “has no such thing as a book watch list.” Brian Glyn Williams, a professor whom the student shared his claims with, said Wednesday that he still believes the student. To date, the student remains anonymous.