The Chinese Swimming Association (CSA) said Sunday Sun Yang had no wrongdoings and did not violate anti-doping rules when he took an out-of-competition urine test last September.
CSA cited a final decision from the FINA Doping Panel, saying "As a result, the sample collection session initiated by IDDM on September 4, 2018, is invalid and void," according to a statement released on Sunday.
Sun had rejected an out-of-competition doping test at his home in Zhejiang province on September 4, 2018, as doping testers from IDDM, the organisation then authorized by FINA to conduct such tests, had failed to show adequate proof of identification.
A dispute between Sun and the doping control team was later referred to world swimming governing body FINA, who ruled in favor of Sun after a 13-hour hearing on January 3.
In the report entitled "Olympic champion Sun Yang abuses drug testers", the Sunday Times reported that Sun "faces a lifetime ban after a clash with doping testers ended in him and his security guard using a hammer to smash a sealed vial containing the swimmer's blood."
It added that Sun "objected to the identification card of the chaperone, there to observe him passing urine, claiming it was insufficient proof he was an official member of the testing team."
The CSA quoted FINA's decision as saying, "Mr. Sun Yang did not commit an anti-doping rule violation under FINA DC 2.3 or FINA DC 2.5" in the statement.
"After FINA called up an investigation of the issue, CSA ordered Sun Yang to fully co-operate with FINA and truely report every details of the affair. According to the final decision of the FINA Doping Panel, FINA confirms the athlete did not commit an anti-doping rule violation," CSA announced in the statement.
Sun Yang, the world record holder of men's 1,500m freestyle and three-time Olympic champion, is considering filing a lawsuit against The Sunday Times, Sun's lawyer Zhang Qihuai said on Sunday.
Zhang said the newspaper reported the incident with "a malign intention" which "severely damaged Sun Yang's reputation and violated his privacy."
"We reserve the right to file a lawsuit against the relevant international media which reported the incident," according to a statement reached to Xinhua.
"The three IDDM staff members failed to produce IDDM authorization letters and were also unable to provide either a DCO certificate or a nursing license," Zhang said in the statement. "And they fabricated an untruthful report claiming Sun Yang broke anti-doping rules and sent it to FINA."
Zhang revealed in a later interview that the doping control team was composed of the chief DCO, her untrained schoolmate and a friend.
"As a matter of fact, the other two people lacked doping control training, DCO certificates and relevant authorization papers," Zhang explained.
According to Zhang, Sun immediately reported the problem to Zhejiang swimming authorities who "consulted with the national swimming team leader and decided to keep the DCOs from taking away the blood sample, since both their identifications and the doping test process were questionable."
Following the incident, Sun and Zhang attended a FINA hearing in November 2018 in Lausanne.
"We provided a great deal of evidence, including 58 video captures and surveillance footage which objectively reproduced the scene," Zhang said. "So FINA concluded that Sun did not commit any wrongdoing."
"Sun is entitled to reject any invalid doping test and safeguard the reputation and integrity of Chinese athletes," Zhang added in the interview.