Denpasar police chief Hadi Purnomo said the suspect, 25- year-old Balinese man Putu Astawa, was arrested early today in Denpasar, Bali's capital.
The burned bodies of Hiroko Matsuba, 73, and her husband Norio Matsuba, 76, were discovered on September 4 by their adopted son in their rented house in southern Kuta, where they had lived for two years.
Purnomo said the man attacked the couple using a knife from their house after they resisted his attempt to rob them of about USD 99, and then burned their bodies to destroy evidence of his crime.
Purnomo said after killing the couple, Astawa drove to Tanah Lot, a popular tourist spot on Bali's coastline about 20 kms from Denpasar, and later returned with fuel to burn their bodies.