TAIPEI (Taiwan News) — The interior ministry said it canceled 10 people’s household registrations on Thursday after it found they had Chinese IDs.

Deputy Interior Minister Wu Tang-an (吳堂安) said the household registrations were canceled after investigations that included contacting the individuals in question, per CNA. Wu said the ministry’s Immigration Agency is investigating more than 30 other people who may hold both documents.

Wu said that if it receives reports from the public about individuals suspected of holding both documents it will contact those people and investigations will proceed from there. He said the ministry would work with the Mainland Affairs Council on a possible legal amendment targeting this issue, if needed.

Mainland Affairs Minister Chiu Chui-cheng (邱垂正) said an increasing number of Taiwanese people hold various forms of Chinese identification and residence permits. He said efforts to create legal amendments to target this issue are underway.

The announcement came after Youtubers released a video that claimed the head of China’s United Front Office in Fujian is Taiwanese and that China provided benefits, including identity documents, to Taiwanese in exchange for producing pro-China content. Wu did not say if Thursday’s announcement was related to the video.