Three people have been found dead at a private residence in Hirakata, Osaka Prefecture, in what is suspected to be a family suicide, police said.

The bodies of office worker Kenji Hayashida, 60, his wife, 55, and their 25-year-old third son were found Wednesday evening by the couple's eldest son, the police said.

The three were found lying in a closed room where charcoal had apparently been burned. The entrance to the house was locked and the window in the room had been sealed with packing tape, they said, alluding to the possibility of carbon monoxide poisoning.

The eldest son, who is in his 30s and lives outside Hirakata, was quoted as saying he visited the house after hearing one of his family members express a desire to die.