Finance Minister Uttama Savanayanan said he has tested negative for Covid-19 after a member of his security detail was earlier confirmed to be infected with the virus.
Mr Uttama announced via Facebook that though test results had shown he is free of the virus, he will maintain a 14-day self-quarantine and work from home as required as part of disease control measures.
Mr Uttama began his 14 days of self-isolation on Wednesday after a police officer providing security for him tested positive for Covid-19, according to Thanakorn Wangboonkongchana, the minister's secretary.
The police officer sat in the front vehicle of the minister's motorcade, said finance permanent secretary Prasong Poontaneat.
Mr Thanakorn said the policeman reported to work on March 11, before feeling ill and going for a check-up which confirmed the infection. Mr Uttama said he was not in the same vehicle as the officer.
Meanwhile, a deputy superintendent at Tao Poon station has become the latest police officer to be diagnosed with Covid-19, Metropolitan Police Bureau commissioner Pol Lt Gen Pakkapong Pongpetra said on Thursday.
This brings the total number of virus-infected police in Bangkok to nine, Pol Lt Gen Pakkapong said.
Meanwhile, Sukhothai governor Maitree Traitilanant said a provincial disease control committee has ordered a 14-day closure of three villages in Kong Krailat district, starting on Thursday, after a couple were confirmed to have been infected with Covid-19.
The villages are Moo 2 Ban Nong Bua, Moo 9 Ban Khlong Yang, and Moo 11 Ban Lai Por Daeng, all in tambon Tachanuam.