About 50 people have been identified as "at-risk" and have self-isolated pending Covid-19 tests after Jarungvith Phumma, the secretary-general of the Election Commission (EC), contracted the virus.
Mr Jarungvith was informed of his test result on Thursday evening, prompting the EC to conduct contact tracing and alert health officials.
Initially, about 50 EC officials came into contact with the secretary-general, according to the EC, among them the EC commissioners who had attended meetings with him.
It remains unclear how Mr Jarungvith caught the virus -- he had not travelled anywhere since the Songkran holiday, according to the EC, who said he had only gone to work at his office and then returned home each evening.
Covid-19 testing was yesterday being arranged for EC executives and staff. It has been reported that EC chairman Ittiporn Boonpracong and four commissioners underwent Covid-19 tests yesterday and that the two other commissioners would be tested at hospitals.
The EC said it was coordinating with the Public Health Ministry and asking it to consider providing vaccine shots for staff.