The investigation into alleged misconduct in the trials of two civil cases heard by the Supreme People's Court (SPC) was completed, said a statement from an investigation team Friday.

The investigation started on Jan. 8 after video footage spread online in which Wang Linqing, an SPC assistant judge, exposed alleged misconduct in the trials of two civil cases, including the mysterious disappearance of files in one of the cases.

Investigations found that Wang stole the files due to a "personal grudge" he held against the SPC and his superior, according to the statement from the investigation team made up of officials from the Commission for Political and Legal Affairs of the Communist Party of China (CPC) Central Committee, the CPC Central Commission for Discipline Inspection and the National Supervisory Commission, the Supreme People's Procuratorate and the Ministry of Public Security.

According to Wang's statement, he tried to sabotage the trial by stealing the case files because his superior decided to remove him from the panel of judges on the case, the investigators said.

The SPC's ruling on the case, which underwent a second trial at the SPC and involved contract disputes between two mining companies in northwest China's Shaanxi Province, was valid, the statement said.

Wang was suspected of illegally obtaining and intentionally leaking state secrets, and his case has been handed over to the police, the statement said.

The investigation team also looked into another economic dispute case, a trial which Wang claimed to have involved irregularities.

The probe found that despite some defects regarding the identification and calculation of the sum of profits involved in the case, the substance of the ruling by the SPC, as the case's appellate court, was right.

The team found that Yan Changlin, a former senior supervisory official with the SPC's supervision bureau, was suspected of accepting requests from one party involved in the case and attempting to meddle in the case, which was handled by Wang at the time.

Wang said he had refused to rule in favor of Yan's acquaintance, and the SPC supervision bureau had later taken actions against him "in revenge" for his refusal to cooperate.

The team noted that Yan was suspected of serious violations of Party disciplinary rules and laws and has been investigated by the anti-graft agency, but the "revenge" claim of Wang was not true.

During more than a month of investigation, investigators held more than 210 interviews with people involved, reviewed over 100 files and documents, carefully examined video and digital evidence and processed information from the public, the statement said.

The investigation team suggested that the SPC should correct the problems exposed, including delayed trials, loose internal management and poor management of confidential documents.