Foreign Ministry officials say they will protest the sentencing of six Cambodians to two years in jail by a Thai court on Monday.
The defendants, four men and two women, were caught collecting rattan on the wrong side of the border earlier this year.
On Friday, a court in Thailand’s Surin province found them guilty of illegal entry and illegal logging.
Foreign Ministry spokesman Koy Kuong said Monday that neither a lawyer nor the Cambodian consul for Surin province was present at the sentencing, in what he called an “irregular” procedure.
“We must take opposition against the verdict,” he said.
The verdict comes after a Cambodian court sentenced a Thai man to 20 years in prison earlier this month, for attempting to lay landmines along the border.
Cambodia and Thailand are engaged in a protracted border standoff and an ongoing diplomatic row.
In 2009, the Thai provincial courts of Sisaket and Ubon sentenced at least 27 Cambodians from 15 months to 9 years in jail for illegal entry and logging in Thai territory.
In the same year, Cambodia’s Banteay Meanchey provincial court sentenced one Thai to three months for illegal entry into Cambodia, although border guards arrested and released another 42 Thais for alleged illegal entry.