Mark Walter acquired the MLB team Los Angeles Dodgers in 2012 along with partners|CC BY 4.0|Prime Minister’s Official Residence

Federal authorities are investigating billionaire Mark Walter’s financial empire after an internal whistleblower complaint led to a broader probe into his business dealings.

The investigation first focused on how Guggenheim Investments, Walter’s asset-management firm, recorded revenue from insurance-related transactions. It later expanded to examine about $16 billion in private credit loans that reportedly passed through a third party before reaching insurance companies owned by Walter.

Walter’s insurers said they found errors in how certain investments were presented after receiving subpoenas. Delaware Life has reclassified $16 billion in investments as affiliated assets.

The Attorney’s Office in Manhattan and the Securities and Exchange Commission (SEC) are investigating whether the transactions violated fraud laws. Insurance companies must disclose related-party deals to regulators to avoid conflicts of interest and protect policyholders.

Walter acquired the MLB team Los Angeles Dodgers in 2012 along with partners. His lending business provided major capital for it.

TWG Global denied any wrongdoing, said it is cooperating with investigators, and expressed confidence that the matter will be resolved. Credit rating agencies have also placed Delaware Life under closer review.