
Officials used drones and climbed risky areas to try to locate Kinya Nakamamura. His relatives said he went missing after visiting the Napapol Phumsiri Pagoda on Doi Inthanon.
Officials searched the mountain until 11pm on Monday.
Jomthong district chief Suthin Chan-ngam said the tourist's relatives reported him missing at 12 noon on Monday.
Nakamamura liked trekking and might have got lost in forests behind the pagoda.
Suthin said villagers at Ban Mae Klang Luang, about 12 kilometres from where the tourist went missing, reported that they saw a tourist wandering near their village.