A smartphone used by the father of an 11-year-old boy who was found dead has a web history of searching for ways to abandon a body, investigative sources said Sunday.

The police department of Kyoto Prefecture is investigating 37-year-old? Y¨±ki Adachi, and the the routes he?took in his car, believing that he attempted to delay the discovery of his son¡¯s body.

Police arrested Adachi on Thursday on suspicion of abandoning the body of his son, Yuki, in a forested area of the city of Nantan in the Kyoto prefecture.?

An analysis of the father¡¯s smartphone found a history of searching for how to abandon a body around March 23, when the boy, a student at Sonobe Elementary School, first went missing, the sources said.

The suspect is believed to have relocated the boy¡¯s body multiple times in Nantan using his car. Investigators suspect that the father temporarily left the body in an area near a public restroom about 2 kilometers northwest of his home.

The boy¡¯s body was later found Monday in a forest about 8 km northeast of the home. While the cause of his death remains a mystery, the boy is estimated to have died in late March.

It remains unknown what happened to the boy after he was last seen by a relative having breakfast on the morning of March 23.

The suspect initially told police that he drove his son to a point near the elementary school and that the boy then went missing. In voluntary police questioning before his arrest, however, the suspect said he strangled his son to death after dropping by the school.

The Kyoto police are investigating the father¡¯s car as part of their probe, suspecting that he knows about the circumstances regarding the boy¡¯s school bag and sneakers possibly worn by the victim, which have been found in different forested areas of the city.