Best Buy CEO and onetime salesman Brian Dunn, 51 and married, is out because, like HP CEO Mark Hurd, he may have used company “assets” to pay for a relationship with a 29-year-old female subordinate.

So say the Wall Street Journal, Bloomberg and Best Buy’s hometown newspaper the Minneapolis Star Tribune.

The Star Tribune said it involved “multiple complaints” of inappropriate behavior with the employee.

The Hurd allegation hasn’t be proved.

Best Buy reportedly won’t talk about its board’s investigation into Dunn’s behavior. It did say it will talk when its audit committee’s probe is done and then “appropriate action will be taken.”

The committee has reportedly got a “high-powered legal” team working on the situation.

Former Best Buy CEO Bradbury Anderson said the investigation couldn’t have come at a worse time given the company’s competitive challenges.

Best Buy, which didn’t immediately disclose the problem when Dunn resigned earlier this week, currently figures it will take a long six to nine months to find a new CEO.

The company is losing money to Internet rivals and Dunn announced a turnaround plan that interim replacement Mike Mikan told employees in an e-mail he means to follow to save $800 million in costs. It would mean closing an undramatic 50 of its 1,100 large US stores, cutting 400 jobs and setting up smaller stores to sell mobile phones.

Dunn was named CEO in 2009.

• Ah, Scandal at Boring Old Best Buy
• Best Buy CEO Out