As of available public records and credible media reporting through 2024, there is no verified instance in which Justin Bieber testified under oath against Sean Combs (Diddy) in a criminal or civil court proceeding.
In the high-profile 2024 trial in which Diddy faced racketeering and sex-trafficking charges in New York, Bieber was neither a listed witness for the government nor a party to the case. Court transcripts, sworn filings, and reputable investigations show no testimony from Bieber that was offered for or against Diddy. This article reviews the primary case, other matters involving both figures, and why the claim endures online.