Vietnam planted border posts between 5 and 50 metres inside Cambodian territory during the late 1980s, researchers from the Royal Academy of Cambodia said yesterday.

Sok Touch, the director of border research at the academy, said there are three distinct sets of border posts – those planted during the French colonial period; those planted during the People’s Republic of Kampuchea (1985 – 1987); and those planted during the current regime.

Of those planted during the People’s Republic, most were planted by Vietnam, and many of these are deeper inside Cambodia than they ought to be, according to Touch.

“It is not fair; most posts were planted 5 metres, some 10 metres, and others about 20 to 50 metres inside Cambodia,” he said.

The lack of global positioning technology at the time may have led to errors, Touch added, noting that Vietnam has not planted any border posts inside Cambodia since the late 1980s.

Koy Pisey, the vice president of Cambodia’s border committee, declined to comment on Touch’s findings, and added that a 2005 treaty with Vietnam was meant to correct “gaps” in an earlier 1985 treaty.

Opposition lawmaker Um Sam An, who has campaigned actively on the border issue, said yesterday the border posts are even deeper in Cambodian territory than the researchers claim.

“Cambodian people lost many hectares of land when the new posts were planted,” he said.