The General Immigration Department said that the program to revoke official documents that were not properly issued, to mostly 70,000 ethnic Vietnamese, was about 70 per cent complete.

Khun Sambo, deputy director general of the department, which is under the Ministry of Interior, said it is yet to complete the exercise to flush out illegal documentation among foreign nationals. The drive, he said, will continue until the end of this year.

“We have not calculated exactly how many cases have been completed so far. We will have a meeting on August 15 to check how many provinces have completed the exercise. The program will continue until the end of the year,” he said.

Sambo said individuals whose documents were revoked need to apply for a residency permit. A two-year permit will cost 250,000 riel ($62.50).

“We are not sure how many will request for the residency permit nationwide,” he said.

A sub-decree passed in August last year allows the authorities to cancel documents such as identity cards, passports and family books (which contains family members’ details) – effectively revoking citizenship from thousands of migrants.

Hundreds of Vietnamese in Kampong Chhnang province are rushing to make the residency card. Kampong Chhnang provincial deputy police chief in charge of immigration, Pal South, declined to comment on the issue.

Local media had reported that 2,034 Vietnamese families live in the province. Most of them are living in Tolesap, including 755 families in Kampong Chhnang town, 806 in Boribor district, and the rest in Kampong Tralach district.

The government plans to issue a two-year residency permit to ethnic Vietnamese who can prove they arrived in Cambodia before 2012.