The department, meanwhile, has closed its 14-storey building in Bangkok’s Samsen area for a day to give it a deep clean.
“Every employee will also be strictly screened,” the department said.
The engineer’s movements have been tracked and the timeline is as follows:
• December 13: Arrived in Samut Sakhon to dine with his family at the Krua Chaophraya Restaurant before stopping off at an ice-cream parlour in Mahachai subdistrict.
• December 14-17: Went to work as normal.
• December 18-20: Visited Si Sa Ket province to cast his vote for the provincial administration organisation poll.
• December 21: Went to work in the morning and was instructed by his supervisor to take a Covid-19 test.
• December 22: He tests positive for Covid-19.