A coronavirus outbreak has been declared at the DVLA's offices in Swansea, the agency has said.
A total of 352 cases of Covid-19 have been identified among workers, including 62 confirmed cases at its contact centre in Swansea Vale, since December 1.
Testing facilities have now been deployed by Swansea University Health Board to the site from Monday until Wednesday for the entire workforce to be tested.
Sion Lingard, consultant in health protection for Public Health Wales, said: "Public Health Wales can confirm that NHS Test Trace Protect has been responding to 62 confirmed cases of Coronavirus in employees at the DVLA Contact Centre in Swansea Vale since the 1 December.
"We are all working in close collaboration with our partner agencies and our priority is to reduce the number of cases in this workforce.
"We would like to encourage all staff at the contact centre to take up the offer of testing available on the site until Wednesday December 23.
"Finding cases early is key to reducing transmission and risks to those around you. But workers in any workplace may be at risk from infection in social or household settings."
Sion Lingard from Public Health Wales continued: “We remind members of the public in Wales that under tier 4 of Welsh Government’s tiered response to coronavirus everyone has a vital role in preventing the spread of Coronavirus. They can do this by always observing social distancing guidelines, washing hands regularly, and adhering to the new restrictions.
“Under the new restrictions, people must stay at home, except for very limited purposes. People must not visit other households or meet other people they do not live with. Those that need to go into a workplace can reduce their risk of infection by following COVID safety precautions at all times.
“We remind the public that the more people that you mix with, the higher the risk of both transmitting and contracting Coronavirus.
“If you or a member of your household develop a cough, fever or change in sense of taste or smell, you must self-isolate immediately and book a free Coronavirus test."