Carrop Lacher, 43, and Cherouana Hicham, 33, were riding a rented motorcycle when they were stopped at a police checkpoint on Rob Koh Road, near Wat Phu Khao Thong at 2.30am.
The two were acting suspiciously and the police asked to search them for illegal items, Pol Maj Litthichai Choomchuay, an inspector at Koh Samui police station, said.
Officers found a screw driver, a number of keys belonging to different bungalows, 15,000 euros (about 660,000 baht) and 5,000 baht in cash and a laptop computer. Mr Hicham was also found to be carrying a fake Indian passport. Police suspected the cash and other items may have been stolen and took them in for questioning.
Shortly after the pair arrived at the police station, a French man, Gerard Chateau, 62, and his Thai wife Naree Aontama, 30, the owners of Aumpa Place resort in tambon Mae Nam, turned up at police station to report the burglary of a guest room. The couple told police they suspected the two Algerians may have been involved in the theft as they left the resort suddenly after the incident without checking out.
Mr Lacher and Mr Hicham later confessed they were behind the burglary at the resort.
The Algerians told police they had broken into hotel rooms and stole money and valuables across the tourist island before being arrested. They would check in for a night at the targeted resort or bungalow and burgle rooms whose guests were away and then fled.
Pol Maj Litthichai said an investigation found the duo had travelled from Malaysia to Samui about a month ago and had changed their accommodation several times since their arrival. They were renting a house in Moo 3 village in tambon Bor Pud when they were caught.
The suspects may have been involved in 20 theft and burglary incidents reported by local hotel operators, he said, adding the crimes had damaged Samui tourism. The complainants had been told to identify the suspects at the police station.
The Algerians have been charged with theft and illegal entry. Mr Hicham also faces a charge of possessing a fake passport.