The CEO of consumer electronics giant Best Buy – Brian Dunn – has resigned, amid mixed messaging over the reasons behind his sudden departure.

The retail giant on Tuesday issued a statement in which it claimed “there were no disagreements between Mr. Dunn and the company on any matter relating to operations, financial controls, policies or procedures.” It added: “There was mutual agreement that it was time for new leadership to address the challenges that face the company.” Director G. Mike Mikan has been named interim CEO to lead the company while a search for a new CEO is underway. Richard Schulze, the founder of Best Buy, continues to serve as chairman.

However, a Reuters report Wednesday said his sudden resignation from the company came during an investigation into allegations of personal misconduct. "Certain issues were brought to the board's attention regarding Mr. Dunn's personal conduct, unrelated to the company's operations or financial controls, and an audit committee investigation was initiated. Prior to the completion of the investigation, Mr. Dunn chose to resign," Claire Koeneman, an external spokeswoman for Best Buy, told Reuters. She would not comment on what the issues were.

Dunn, a 28-year veteran of Best Buy who had risen up the internal corporate ladder (starting as a sales executive), was facing strong pressure to get the company to more closely compete with its Internet rivals. Indeed, Dunn announced only last month that Best Buy planned to shutter 50 of its US big-box electronics stores over the next year after losing US$1.7 billion in its latest quarter. At the same time the company said it was to open 100 more smaller-format stores focusing on mobile phones and tablets.

The company’s challenges were highlighted by Dunn in a recent interview with Mobile World Live, where he admitted the company needed to do a better job of complementing its ‘brick-and mortar’ retail outlets with a state-of-the-art online offering. “It’s really important that we get our website and our ecommerce engine and our mobile commerce engine connected more seamlessly and that’s what we’re working on,” he said at the 2012 GSMA Mobile World Congress.

View the full interview – one of Dunn’s last as Best Buy CEO – here.