— Greg Lindberg, the Durham investor who went from political obscurity to the state's largest campaign donor over the last two years, is the target of at least one federal grand jury subpoena seeking a trove of documents about his business dealings.

A subpoena issued last month to the state Department of Insurance, which regulates a number of Lindberg's companies, indicates that a federal investigator with a background in white-collar crime and an FBI forensic auditor are involved. The subpoena came from U.S. Attorney for the Western District of North Carolina Andrew Murray's office in Charlotte.

"An official criminal investigation of a suspected felony is being conducted by an agency of the United States and a federal grand jury," the cover letter states. An attached notice states that the "subpoena relates to an investigation of drug offenses, crimes against financial institutions, or money laundering crimes."

Attempts to reach Lindberg for comment, both through a phone number for him that appears in DOI email records and through a trio of attorneys who have represented him, were not successful Tuesday. The U.S. Attorney's Office in Charlotte declined to comment, as did a spokeswoman for the FBI.

The subpoena seeks a broad range of documents going back to January 2014, essentially requiring the DOI to produce all of the records it has from the period relating to Lindberg and eight listed companies, including Eli Global and Global Bankers Insurance Group, both main holdings for the wealthy Durham investor.

A source who has spoken to investigators said they were told there are multiple subpoenas in the case, and the investigation appears to span multiple states. Some of the companies listed on the DOI subpoena are based out of state.

The investigation has been in progress for much, if not all, of 2018, the source said.

Federal investigators have also reached out to the North Carolina Republican Party for information, Executive Director Dallas Woodhouse confirmed. Lindberg has given the party nearly $2 million over the last year or so. He began giving this year to the North Carolina Democratic Party as well, putting at least $500,000 into party operations and its building fund either personally or through one of his companies.

The subpoena served on the DOI lists an FBI forensic accountant as one of the investigators. It also lists Assistant U.S. Attorney Daniel Ryan, who has a history in complex financial fraud cases. Ryan was part of the federal mortgage fraud case against Bank of America that culminated in 2014 with the largest civil settlement with a single entity in U.S. history: $16.5 billion.

Lindberg has given more than $5.2 million to North Carolina political campaigns in less than three years. He has declined repeatedly to answer media questions about it.

Other key employees from Eli Global and Global Bankers Insurance, which are among the more than 300 companies Lindberg has registered, have given to state political campaigns as well.

Lindberg is Lt. Gov. Dan Forest's largest donor as Forest heads into an assumed 2020 run for governor, giving $2.4 million to a pair of political groups that support Forest and can take unlimited donations. Forest said Tuesday that he'd heard an investigation existed and that Lindberg's name had been mentioned in connection with it.

"Whether he's under investigation, I have no idea," Forest said. "Right now, I don't know anything about it.”

Forest's office and his campaign said investigators have not reached out to them.

Lindberg's first major foray into North Carolina politics came in 2016, when he put $350,000 into a PAC called the N.C. Opportunity Committee, which supported then-Insurance Commissioner Wayne Goodwin's re-election bid. Lindberg donated another $10,000 directly to Goodwin's campaign, the maximum allowed under state campaign finance rules at the time.

Goodwin now chairs the North Carolina Democratic Party. He has frequently declined to discuss Lindberg, and he did not return a message seeking comment Tuesday. A spokesman for the Democratic Party declined to comment.

Minutes from a party executive council meeting after Lindberg made his six-figure contributions to the Democratic Party quote Executive Director Kimberley Reynolds as saying Goodwin "personally obtained" the $250,000 building fund donation and that he "should get all the credit for it."

Months after Republican Mike Causey beat Goodwin in the 2016 insurance commissioner's race, Lindberg sent Causey's campaign $5,000. Another $5,000 came the same day from Lindberg's wife.

Both donations came in a week Causey was due to meet with Lindberg about his insurance businesses, the commissioner said, and his campaign returned the money.

"There was an ongoing, just a routine financial examination, and out of an abundance of caution, we didn't want any questions to be raised,” Causey said.

Two of Goodwin's top lieutenants at the insurance department – former deputy commissioners Ray Martinez and Louis Belo – went to work for Lindberg's companies soon after Goodwin lost his re-election bid in 2016. An attempt to reach them Tuesday at the main phone number for Global Bankers Insurance was not successful.

Lindberg has given to insurance commissioner candidates in at least three other states: Georgia, Oklahoma and Washington, according to followthemoney.org, which has a partial database online of state-level giving in multiple states.

Other executives within Lindberg's empire give as well. The Atlanta Journal Constitution reported earlier this year that at least 11 employees and board members at Eli Global or Global Bankers Insurance gave to Republican insurance commissioner candidate Jay Florence's campaign.

Eli Research put another $200,000 into a group called "Insuring America's Future," which sent out mailers supporting Florence, the newspaper reported, making the company this group's largest donor by far.

In 2017, Goodwin invited people in North Carolina, including Lindberg, to a fundraiser for Florence, though the event was ultimately canceled. Democratic Party spokesman Robert Howard said Goodwin simply forwarded an emailed invitation to approximately 100 people he had contacts for, both in his private capacity and as part of his consulting business, Seaboard Strategic.

"Wayne has worked for more than two decades in the insurance regulatory business and in his law practice, forging personal and professional relationships with Democrats and Republicans across the country," Howard said in an email.