A young boy and a woman were found dead in Lorong Sesuai near Bukit Batok Nature Park yesterday.
The police said they were alerted to the two cases of unnatural deaths along Lorong Sesuai at 6.42am.
The boy, five, was found motionless in a car while the woman, 41, was found lying motionless nearby.
They were pronounced dead by a Singapore Civil Defence Force paramedic at the scene.
The two individuals were confirmed to be Japanese nationals.
A spokesman for the Japanese embassy said that it was providing consular assistance to the next of kin to collect the two bodies.
Lorong Sesuai is located near Bukit Batok Nature Park, with part of the road within a restricted area.
When Chinese-language newspaper Shin Min Daily News visited the scene of the incident, a police cordon had been erected across part of Lorong Sesuai which has a sign indicating that the land is state property and that no trespassing is allowed. A police car was also seen nearby.
Shin Min reported that the police searched the area for close to six hours.
The police said they are investigating the two cases.
This article has been edited for clarity.