Gov. Robert F. McDonnell, who kept a low profile during the governor’s race because of an ethics scandal, will appear at a fundraiser this week for state Sen. Jeffrey L. McWaters.

McDonnell (R) is the subject of state and federal investigations into more than $160,000 in gifts and money described as loans that a Virginia businessman provided to the governor and his family. McDonnell has apologized and returned the gifts and money but has also said he provided no state favors to Star Scientific’s chief executive, Jonnie R. Williams Sr.

The scandal led Attorney General Ken Cuccinelli II (R), who had his own ties to Williams, to distance himself from the sitting governor during his race to succeed him. Cuccinelli lost the contest this month to Democrat Terry McAuliffe.

McWaters (R-Virginia Beach), who says he is taking “an interested look” at challenging U.S. Sen. Mark R. Warner (D) in 2014, said he had no concerns about appearing with McDonnell.

“None whatsoever,” he said.

“He’s been a longtime family friend of mine, and his family’s been friends of mine,” McWaters said. “From my perspective, it’s kind of a ‘Thank you, governor, for four great years.’ ”

McWaters said he hadn’t announced that McDonnell was going to attend the event, which will be closed to the news media and is expected to draw about 200 people to McWaters’s home Thursday.

“It was going to be kind of a surprise,” he said.

But McDonnell’s PAC, which in recent months has rarely had any political events to announce, included it in its weekly listing of events.

McWaters, a retired health-care executive who founded insurance company Amerigroup, said that he has received a lot of encouragement to challenge Warner but that he is not actively running. The Thursday fundraiser is for his state Senate seat.

“I’m taking an interested look at this,” he said. “Like every politician, we look at these things from time to time. . . . Mark’s a good guy and extremely likable, but he happens to be on the wrong side of many issues.”