Virginia Gov. Bob McDonnell (R) in February 2010. (Joshua Roberts/Reuters)

Gov. Robert F. McDonnell sought to assure Virginians on Tuesday that he is able to do his job as governor and not be distracted as the FBI explores the relationship that he and his wife have with the businessman who helped pay for their daughter’s wedding.

McDonnell’s remarks were his first extensive comments following revelations in The Washington Post in late March that Star Scientific chief executive Jonnie R. Williams Sr. paid the $15,000 catering tab at Cailin McDonnell’s June 2011 wedding.

The controversy also has extended to Attorney General Ken Cuccinelli II, the presumptive Republican nominee for governor, who initially failed to disclose substantial stock holdings in Star and personal gifts from Williams.

In an hour-long radio interview, McDonnell (R) denied any wrongdoing. But he acknowledged that the gift from Williams could raise questions and that it had created pain for his family. The issue trailed McDonnell into the afternoon, when he was asked about it at a Council on Foreign Relations forum. McDonnell had traveled to Washington for that event to discuss the across-the-board federal spending cuts known as sequestration but found himself defending the role he and his wife played in promoting Star.

“I’ve had a remarkable opportunity to serve these last 31 / 2 years, and there’s nothing going on at all that impairs my ability to do a good job and to serve the people of Virginia,” McDonnell said on WTOP.

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

McDonnell offered his most complete defense of his actions to date at the two appearances, saying he never did any favors for Williams or his company in exchange for campaign contributions and personal gifts.

“I’ve been blessed to have a lot of friends,” he said. “And Mr. Williams and his wife, Celeste, have been family friends for four or five years. But I think it’s important for the people of Virginia to know nothing has been done with regard to my relationship with Mr. Williams or his company, Star Scientific, to give any kind of special benefits to him or his company.”

The governor’s comments came on the day The Post reported that FBI agents are conducting interviews about the McDonnells’ links to Williams and actions they have taken to promote the dietary-supplement maker. McDonnell, asked about it on the radio program, said it was his practice never to comment on ongoing criminal cases — a reference to the felony embezzlement case of the former mansion chef who catered the wedding.

Three days before the wedding, first lady Maureen McDonnell traveled to Florida to address a group of investors about Star’s supplement, sold under the brand name Anatabloc. The governor and wife later hosted a luncheon at the mansion to mark the product’s arrival in stores.

At the District forum, McDonnell said that his wife’s actions on behalf of Star were consistent with her longtime interest in “nutraceuticals” and her efforts as first lady to help boost Virginia businesses.

“My wife is the first lady,” he said. “You know how much she gets paid? Zero. She’s a volunteer. She’s done a very good job as first lady.”

McDonnell also spoke of his struggle to be a “normal citizen dad” amid the pomp of the governor’s office. Former mansion chef Todd Schneider suggested in a court motion last week that McDonnell’s five adult children had taken large quantities of food and liquor to their own homes or college dorm rooms.

“While I’m the governor of Virginia, I try to . . . have a normal family life,” he said on WTOP. “And sometimes when you’re working in a normal family, things aren’t exactly pretty, whether you’re a governor or whether you’re a normal citizen. I try to be a normal citizen dad as much as possible. . . . We’re normal people, and I’m proud to be the dad of five kids. I think I’ve got great kids. I’m blessed to have them. But you know, we are a normal family with all the ups and downs and pains and travails of any other normal family.”

Under Virginia law, elected officials may accept gifts of unlimited value if they disclose those worth more than $50. McDonnell did not report the wedding payment, but on the radio show, he stood by his contention that there was no need to do so because it was a gift to his daughter, not him. The law does not require gifts to immediate family members to be disclosed.

But McDonnell also acknowledged for the first time that the gift could “raise eyebrows,” as WTOP host Mark Lewis put it. Because the father of the bride often pays for weddings, Lewis said, “there’s a blurred line there as to who the real recipient of the gift was.”

“I do understand that,” McDonnell responded.

Asked whether he had any regrets and if in hindsight he wished the wedding payment had not been accepted, McDonnell said: “The decision really ultimately was my daughter’s. That’s hard to say in retrospect. Obviously, there’s been a lot of attention to that. It’s caused a fair amount of pain for me personally.”

Errin Whack contributed to this report.