A billionaire businessman has admitted conspiracies involving misuse of $US2 billion ($3.1 billion) of company funds to defraud US insurance regulators and thousands of policyholders.

Court documents show Greg Lindberg, from Tampa in Florida, conspired with others on the fraud from about 2016 to 2019. He directed cash through a web of companies based in North Carolina, Bermuda, Malta and elsewhere.

“Lindberg’s elaborate network of investments, insurance companies and financial deals was designed to exploit the insurance system and drain millions from policyholders to enrich himself at the public’s expense,” the FBI’s Special Agent in Charge Rober DeWitt said.

Companies Lindberg controlled invested more than $US2 billion in loans and other securities with his affiliated companies and laundered the scheme proceeds, court documents say.

Authorities say 54-year-old Lindberg directed the scheme and benefited from the fraud in part by “forgiving” more than $US125 million ($192 million) in loans to himself from the insurance companies he controlled.

“Thousands of policyholders suffered substantial financial hardship as a result of Lindberg’s fraud scheme, which left multiple companies in or on the brink of liquidation.” Principal Deputy Assistant Attorney General Nicole Argentieri said.  

Lindberg pleaded guilty to one count of conspiracy to commit offences against the US, including wire fraud, investment adviser fraud and crimes in connection with insurance business, and one count of money laundering conspiracy.

He faces a maximum of five years in prison on the conspiracy against the US count and 10 years for the laundering. He is also yet to be sentenced on another conviction.