High-ranking Immigration Department officials confirmed yesterday that the government will continue to roll out its programme to strip “improper” documents from ethnic Vietnamese across the nation following a “pilot” in Kampong Chhnang that has already affected thousands of residents.

“We will continue doing this to other provinces,” said department Director Sok Phal.

Keo Vanthorn, the department spokesman, said Kampong Chhnang was treated as the pilot province because of a high concentration of ethnic Vietnamese. “We used Kampong Chhnang because in that area there are many Vietnamese people living in floating villages,” he explained.

Officials have previously said as many as 70,000 ethnic Vietnamese residents were subject to the documentation purge, though there has been scant information about what steps will follow.

Ethnic Vietnamese residents who had their documents revoked told The Post on Monday that they were born in Cambodia and had ties to the Kingdom going back multiple generations. Most had only spent a few years in Vietnam when the Khmer Rouge were in power. Many surrendered all documentation Monday, effectively rendering them stateless.

Read more: Ethnic Vietnamese, some living in Cambodia for generations, see documents revoked

According to Vanthorn, however, those whose documents were revoked were “migrants”, and needed to fill out paperwork for documents identifying them as such. “They were supposed to apply a long time ago because they have been migrants for a long time in Cambodia. They never should have received Cambodian documents, because those passports and identity cards are for Cambodians,” he said.

“They need to pay for illegally living there,” Vanthorn added, saying they may be able to apply for citizenship at a later date.

Cambodia’s citizenship law has long been criticised as overly vague, and a paper published this year by human rights researcher Christoph Sperfeldt argues that it was configured specifically to marginalise ethnic Vietnamese and Chinese populations.

The current law, drafted in 1996, uses the ethnic term “Khmer” rather than the nationality “Cambodian” when discussing citizenship – though it also states that citizenship is granted to “any child who was born from a foreign mother and father . . . who were born and living legally in Cambodia”, as was the case of many of the so-called migrants interviewed by The Post.

Complicating citizenship, however, is the fact most archival records were destroyed during Khmer Rouge rule, making it difficult to prove a longstanding presence in Cambodia.

A 2014 report by Sperfeldt and researcher Lyma Nguyen concluded that many Vietnamese living in Kampong Chhnang could already be classified as “stateless”. “Cambodian authorities do not regard members of the focal group as Cambodian nationals . . . it appears that Vietnamese authorities do not currently view the focal group as Vietnamese citizens,” they wrote.

A 1954 UN convention made it illegal to “arbitrarily deprive” nationality, but Cambodia is not a signatory.

Phil Robertson, with Human Rights Watch’s Asia division, said rendering ethnic Vietnamese stateless was “a clear violation of their human rights”.