Virginia Gov. Bob McDonnell speaks to the press at the Capitol in Richmond in this February file photo. (Steve Helber/Associated Press)

FBI agents are conducting interviews about the relationship between Virginia Gov. Robert F. McDonnell, his wife, Maureen, and a major campaign donor who paid for the food at the wedding of the governor’s daughter, according to four people familiar with the questioning.

The agents have been asking associates of the McDonnells about gifts provided to the family by Star Scientific chief executive Jonnie R. Williams Sr. and actions the Republican governor and his wife have taken that may have boosted the company, the people said.

Among the topics being explored, they said, is the $15,000 catering bill that Williams paid for the 2011 wedding of McDonnell’s daughter at Virginia’s historic Executive Mansion. But questions have extended to other, previously undisclosed gifts from Williams to Maureen McDonnell as well, they said.

The interviews, at which Virginia State Police investigators were present, began in recent months as an outgrowth of a federal investigation of securities transactions involving Star Scientific, which produces a dietary supplement called Anatabloc. The company disclosed that probe in a regulatory filing last month, saying it had received subpoenas from the U.S. attorney’s office for the Eastern District of Virginia.

Now, federal officials are trying to determine whether to expand that investigation into a broader look at whether McDonnell or his administration took any action to benefit Star Scientific in exchange for monetary or other benefits, according to the four people familiar with the interviews. It is unclear whether the probe will be broadened.

Previous Washington Post coverage of Gov. Bob McDonnell and ties to Star Scientific.

U.S. Attorney Neil H. MacBride declined to comment, as did spokesmen for the FBI’s Richmond division and the state police.

Tucker Martin, a spokesman for McDonnell, a possible 2016 presidential contender, said, “It is the policy of the governor’s office to not comment on any possible investigations.”

Jerry Kilgore, an attorney for Williams, also declined to comment.

McDonnell previously has said that he and his wife have known Williams for about five years, that they consider him a personal friend and that the first family’s efforts on behalf of Virginia-based Star Scientific are typical of what any governor would do to promote the state’s businesses and products.

But the FBI interviews represent a potential escalation of the growing controversy about McDonnell and his wife’s relationship with Williams, which has consumed the state capital in recent weeks.

Williams and Star Scientific have given McDonnell and his political action committee more than $120,000 in publicly disclosed campaign donations and gifts, while the McDonnell family has received other benefits, such as a vacation at Williams’s lake house in western Virginia.

The McDonnells have taken actions to promote Star Scientific, including allowing the company to hold a 2011 luncheon marking the launch of Anatabloc at the governor’s mansion.

The focus of the FBI interviews has been to determine whether any of those actions constituted a quid pro quo — McDonnell using his office to promote the company in return for anything of value for him or his family — people familiar with the questioning said.

Star Scientific does not appear to have received state incentive grants or other financial assistance during McDonnell’s term, according to documents obtained through a Freedom of Information Act request to the Virginia Economic Development Partnership, the leading state agency that manages such programs.

But if investigators gather enough other evidence, they may open a formal public corruption inquiry, the people said. They spoke on the condition of anonymity because the interviews are private and they are not authorized to discuss them.

Agents and state police investigators are reviewing Star Scientific’s financial records, the campaign donations and other records, the people said.

The revelations about the FBI interviews came as new documents filed in a Virginia court Monday said that a former chef at the Virginia governor’s mansion, who catered the wedding, turned over information about Williams and the McDonnells to state and federal authorities more than a year ago.

The former chef, Todd Schneider, is seeking the dismissal of charges that he embezzled from the kitchen while working in the mansion in 2010 and 2011.

It is unclear what role those documents played in triggering the FBI interviews about the relationship between the McDonnells and Williams.

People familiar with the interviews said they began as part of the securities investigation of Star Scientific. The company has informed investors that its executives think the investigation is “principally focused” on its securities transactions.

McDonnell has repeatedly declined to say whether Williams gave undisclosed gifts to members of his family. Virginia law allows elected officials to accept gifts of any size, provided those worth more than $50 are disclosed on forms filed annually. State law does not require elected officials to disclose gifts that are given to members of their families.

According to documents obtained by The Washington Post, McDonnell signed the contract for the catering at his daughter Cailin’s 2011 wedding. He also paid two deposits for the event. When Williams’s check overpaid the total catering bill, a $3,500 refund check from the catering was made out to Maureen McDonnell and not to Williams or the newly married couple.

The wedding gift was one piece of a close bond between Williams and the McDonnells. Three days before the wedding, Maureen McDonnell flew to Florida, where she spoke at a gathering of doctors and investors interested in learning more about a chemical used in Anatabloc. She told the group that she supported Anatabloc and believed it could be used to lower health-care costs in Virginia, attendees have said.

In July 2011, the McDonnell family vacationed at a lake house owned by Williams and drove the executive’s Ferrari from the home, at Smith Mountain Lake southeast of Roanoke, back to Richmond. The lake house vacation was disclosed by the governor.

In August 2011, the McDonnells allowed Star Scientific to hold an event promoting Anatabloc at the governor’s mansion. A spokesman for the governor has said the luncheon, hosted by Maureen McDonnell, was paid for by the governor’s political action fund. The governor attended briefly, to acknowledge grants Star Scientific was handing out to public universities, the spokesman said.

A picture of th governor smiling and holding up a bottle of Anatabloc was featured on the product’s Facebook page until it was removed after the publication of a Post article late last month detailing the relationship between the governor and Williams.

McDonnell’s spokesman has said he does not remember when the picture was taken and did not authorize its use by the company.

Alice Crites contributed to this report.

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