US doughnut maker and retailer Krispy Kreme has said it has been notified by the US Securities and Exchange Commission that it has entered a formal order of investigation concerning the company.

The company did not give further details. At the end of July the company revealed that the SEC was conducting an informal, non-public inquiry regarding the company.

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

The doughnut company said at the time that it was 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," chairman, president and CEO Scott Livengood said in July.