A jobless chef arrested in the Yard Friday for having stolen a book from the Law Library is now suspected of being a Communist spy. Four Boston Federal Bureau of Investigation agents questioned the man yesterday at Cambridge Police headquarters, where he is being held on a charge of suspicion of larceny.

Cambridge police detective Alfred C. Marckini first suspected the 36-year-old man of Communist sympathies when he found his brief case filled with Red literature, a letter from the Coast Guard refusing him employment as a bad security risk, and a congratulatory note from an unnamed Maine politician.

The note said in part, "In closing, please send us another one of your wonderful letters. They are a great help to our cause."

The man will be arraigned today in East Cambridge District Court.

In the briefcase police found four books, all from the Law Library. They were: a volume on Civil Rights, a history of the American political movement, review of recent Civil Rights cases, and a copy of the Princetonian. The librarian called the police when the man signed out for three books and left the library with four.

Mapped Logan Airport

Police reported that the man is a graduate of Boston Latin High School and Boston University. In his car, parked near the Yard, Cambridge police detectives William Trodden and John Norton found a map on which Logan Airport and the Bethlehem Steel Company's shipyard at Fore River were plotted out.

Contacted last night at Woods Hole, Mass., Norman T. Allen, Personnel Director of the Oceanographic Institute there, said that the suspect worked as a seaman on the Institute's vessel, "Atlantis," during a spring cruise to Cannes, France and Recife, Brazil.