James Pattinson 
The Spanish Hawk [PDF ebook] 

There were five dead men in the cabin of the boat, lying under six fathoms of Caribbean water. But the men had not been drowned-they had been shot through the head at close range. John Fletcher had gone down to photograph a sunken ship, but he took photographs of the boat and its cargo of dead men instead. Soon he is having trouble with the island police, some men from President Clayton Rodger’s private army of thugs, and two CIA agents. Now Fletcher wishes he had followed his first impulse and said nothing to anyone.