Who is Dr. Frederick Harrison from To Have and Have Not and what is their importance?

Dr. Frederick Harrison is an important figure in the U.S. Administration. He and his unnamed secretary are fishing on Capt. Willie Adams' boat when it passes Harry Morgan's shot-up booze boat. Ruddy faced and high-cheekboned, with deep-set gray eyes and a contemptuous mouth, Harrison wants to take Morgan's boat into custody, but he is thwarted by Adams and settles for swearing an affidavit that gets it impounded.