Three people working at Government House have been diagnosed with Covid-19 and the premises are being closed for cleaning.
The building will be closed to news reporters and photographers from April 29-May 7, Natriya Thawiwong, an adviser to Prime Minister Prayut Chan-o-cha, announced on Tuesday.
Government House will instead publish its news briefings online via Factbook and LINE, Ms Natriya said.
About 95% of Government House officials will be working from home.
Gen Prayut had instructed the spokesman's office to quickly inform the media, Ms Natriya said.
A Government House source said three people who worked there had tested positive for Covid-19.
They were the driver of Seksakol Atthawong, who is a vice minister at the PM's Office, a housekeeper and a Special Branch police officer.
Mr Seksakol's driver tested positive on April 23 and the other two on April 25.
Government House officials who had been in close contact with them had been asked to go into isolation, the source said.
Mr Seksakol said his driver had been admitted to Bamrasnaradura Infectious Diseases Institute for treatment.
Although he had not been in close contact with the driver recently and had received two Covid-19 vaccine doses, he had still been tested twice for the virus - once at Pak Chong Hospital in Nakhon Ratchasima and also at the Bamrasnaradura Infectious Diseases Institute. Both results were negative.
Despite being negative, he had placed himself in home isolation. Therefore, he had not been in close contact with Gen Prayut since learning about his driver's contagion, Mr Seksakol said.