The World Anti-Doping Agency announced on Tuesday that it has lifted the suspension of China Anti-Doping Agency, which was closed because of technical mistakes.
"WADA is pleased to confirm that the Beijing laboratory's accreditation has been reinstated just ahead of the maximum four-month suspension that was issued in April," said WADA Director-General Olivier Niggli.
"We are confident that the laboratory has corrected its deficiencies and will now be operating to the high standards required by WADA."
The reinstatement allows the Beijing lab to immediately resume all of its anti-doping activities, including all analyses of urine and blood samples, according to a statement on the agency's website.
It banned the Beijing lab on April 22 after the lab failed a technical test in October, according to the lab's chief, Xu Youxuan.
The Beijing lab reported two false negative results in WADA's double-blind tests, Xu said.
Double-blind testing means the lab carried out the test without knowing the subjects of the testing, so as to create an unbiased test environment.
The lab's suspension spanned China's preparation for the Rio Olympic Games and forced it to send samples to other accredited labs.
WADA is responsible for accrediting and reaccrediting anti-doping labs to ensure that they maintain the highest standards.
Whenever a laboratory does not meet international standards, the agency may suspend the accreditation. Of the 35 accredited labs throughout the world, 19 have been suspended.
During the suspension, the Chinese laboratory was required to take five remedial steps, in addition to addressing non-conformities identified in its external assessment and during WADA site visits.