In March 2023, in an investigate report published for Global News, Cooper alleged that Liberal Party of Canada Member of Parliament Han Dong had advised a Chinese diplomat to extend the detention of Michael Spavor and Michael Kovrig. Following a subsequent libel lawsuit issued by Dong, Cooper's reporting was criticized by reporters and national security commentators for failing to verify his sources' claims, with the judge finding Global News had no documentary evidence supporting Cooper's claims. As part of a 2025 settlement with Dong, Global News issued a statement recognizing the findings of the final report of the Public Inquiry into Foreign Interference, which found that classified intelligence corroborated Dong's denial of Cooper's reporting.
In September 2024, Cooper published a report in The Bureau claiming to show video evidence of Bill Majcher, a former RCMP undercover operative accused of assisting Chinese intelligence, meeting with drug trafficker Tse Chi Lop in a Macau casino. Journalist Nury Vittachi noted that the purported video footage actually was from the 2014 action-comedy movie From Vegas to Macau, starring Chow Yun-fat.