The suspects were walking in a forest grove near Ban Klong Luek in Aranyaprathet district in order to cross the border back to Cambodia's Poipet.
They confessed they had illegally entered Thailand several months ago to work in the eastern provinces of Rayong and Chonburi.
They were on their way back to Cambodia in order to make ID cards in preparation for their national election next year.
Thai local authorities sent the 38 Cambodians to Sa Kaeo's immigration police for futher legal action.
