Although his autobiography was published by a division of Simon & Schuster Inc., Cain paid Stockbridge, Georgia-based T.H.E New Voice Inc. $36,511 for books. His campaign spent $4 million through Sept. 30, including more than $64,000 paid to his motivational speaking company for airfare, lodging and supplies, as well as the books.

“They are buying my books and my pamphlets,” Cain said in an interview in between appearances in Arizona yesterday. “The campaign is buying them from T.H.E New Voice.”…

Bill Allison, editorial director at the Washington-based Sunlight Foundation, a nonpartisan group that tracks political money, said the transactions deserve scrutiny.

“All candidates publish books and they offer them as premiums to donors, but most candidates aren’t buying them from their own companies,” he said. “It raises the question of his campaign contributions ending up in his own pocket.”