US doughnut maker and retailer Krispy Kreme has said that the US Securities and Exchange Commission is conducting an informal, non-public inquiry regarding the company.

Krispy Kreme said the inquiry generally concerns the company's franchise reacquisitions and its previously announced reduction in earnings guidance.

The doughnut company said it is fully cooperating with the SEC in response to its request for information.

"Krispy Kreme has no higher priority than the confidence of our shareholders, customers and employees. While we are confident in our practices, we understand and respect the SEC's responsibilities and will continue to cooperate fully throughout this process," said chairman, president and CEO Scott Livengood.