All plant workers had tested negative for the respiratory disease caused by the novel coronavirus, a spokesman for SK Hynix said. A Korean worker whose initial positive test result had prompted the shutdown subsequently tested negative, he added.
The Korean worker, who had worked at the Chongqing plant since February, tested positive for COVID-19 on arrival at Incheon airport in Seoul last week, though he did not display symptoms, China's Xinhua agency reported on Sunday.
A statement on Chongqing municipality's official WeChat account said that 8,412 people, including close contacts and "general contacts" of the worker, tested negative for the disease.
Environmental samples from SK Hynix and a Chongqing hotel, including the worker's place of work and residence, also tested negative, the statement said.
SK Hynix, the world's No.2 memory chip maker, employs about 2,700 workers in the Chongqing facility, including some Koreans.
(Reporting by Joyce Lee; Additional reporting by Andrew Galbraith in Shanghai; Editing by Leslie Adler and Ramakrishnan M.)