At least four senior officials from a district in Chiang Mai are accused of unlawfully issuing Thai identification cards to more than 18,000 unqualified immigrants, the Department of Special Investigation (DSI) said yesterday.

DSI chief Tarit Pengdith said the probe found that 18,587 foreign immigrants had been added unlawfully to the database of Wiang Haeng district as eligible recipients of Thai IDs.

Read more: The Nation