A man in his 60s confirmed to have been infected with the COVID-19 virus drove a total of 10 Kyodo News staff members in a hired vehicle from late January to early February, the news service said Tuesday, confirming that it had notified member organizations.

In a statement sent to media organizations Monday, Kyodo said it had instructed the 10 workers to stay at home from that day, and that none of them had shown any symptoms.

More than 14 days, or the probable incubation period of the disease, have already passed for seven of the 10 who rode in the vehicle, Kyodo said.

The remaining three will stay at home for 14 days in total, while the seven will soon return to work, Kyodo said, citing guidance from a public health center.

The health center is said to have told Kyodo it would not conduct COVID-19 tests on the staff because none of them have shown symptoms.

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There has been speculation that those exposed may include reporters who are members of the press club at the Prime Minister’s Office in Tokyo. According to a report Monday by the Yomiuri Shimbun, news media firms that have membership of the club were among organizations that received the notice from Kyodo.

Reporters at the press club frequently meet high-ranking officials at the Prime Minister’s Office.

When contacted by The Japan Times, Kyodo declined to comment on whether any of the workers are reporters.

The Tokyo Metropolitan Government announced Sunday that the driver involved had tested positive for the novel coronavirus.