Federal authorities are investigating about $16 billion in private-credit deals involving Mark Walter's insurance companies following an internal whistleblower complaint. The probe by the U.S. Attorney's Office in Manhattan and the Securities and Exchange Commission examines whether fraud occurred in how Guggenheim Investments booked revenue from dealings with insurers.

The investigation evolved to focus on investments in private credit, which supplied financial firepower for Walter's 2012 acquisition of the Los Angeles Dodgers. Authorities are examining how loans extended to companies tied to Walter or his conglomerate, TWG Global, wound up on the books of insurance companies he owns after passing through a third entity.

Such related-party transactions must be disclosed to insurance regulators to limit conflicts of interest and protect policyholders. Walter's insurance firms said they identified problems with how certain transactions were presented after receiving subpoenas.

The probe threatens the complex empire assembled by the 66-year-old, whose profile rose from ownership stakes in the Dodgers, Los Angeles Lakers, and Chelsea Football Club. On Thursday, he appeared at the White House celebrating the Dodgers' 2025 championship.