BEIJING (AP) — The first scientist to publish a sequence of the COVID-19 virus in China said he was allowed back into his lab after he spent days locked outside, sitting in protest.

Zhang Yongzhen wrote in an online post early Wednesday that authorities had “tentatively agreed” to allow him and his team to return to his laboratory and continue their research for the time being.

Zhang had been staging a sit-in protest outside his lab since the weekend after he and his team were suddenly notified they had to leave their lab, a sign of Beijing’s continuing pressure on scientists conducting research on the coronavirus.

The Shanghai Public Health Clinical Center previously said Zhang’s lab was being renovated and was closed for safety reasons. But Zhang said his team wasn’t offered an alternative until after the eviction and the new lab didn’t meet safety standards for conducting their research.

Zhang’s latest difficulty reflects how China has sought to control information related to the virus: An Associated Press investigation found that the government froze meaningful domestic and international efforts to trace it from the first weeks of the outbreak. That pattern continues to this day, with labs closed, collaborations shattered, foreign scientists forced out and Chinese researchers barred from leaving the country.