A day earlier, they complained to the police in Cao Bang that their backpack containing a laptop, flycam, and some VND10 million (US$409) in cash had been robbed by a stranger, Cong An Nhan Dan newspaper reported.
Police investigated their claims and found no evidence of a robbery.
At the police station, the two foreigners admitted that they had lied about their robbery to receive a confirmation letter from authorities about the loss of property.
The tourists had bought travel insurance before visiting Vietnam and the insurance company was liable to pay between 80-90% of the value of their lost belongings.