Helen Holly Roth-Franta (born March 30, 1916) was an American crime writer. She authored novels and short stories in the genres of spy fiction and detective fiction. She also published works under the pseudonyms P.J. Merrill and K.G. Ballard. She published twelve novels in her lifetime and many short stories, one of which was nominated for an Edgar Award. In 1964, Roth disappeared off the coast of Morocco while sailing on a ketch with her husband and is presumed to have died.