"I will fully cooperate with the investigation," the 66-year-old told reporters before entering the prosecutors' office, declining to further comment on his alleged involvement in irregularities. Nam has been accused of violating a string of laws by giving business favors and getting involved in accounting fraud at the company.

Prosecutors suspect that Nam gave business favors to a local logistics company owned by his friend, and siphoned off 12 billion won ($10 million) of company funds between 2010 and 2013.

The summons came a few weeks after the country's state auditor said the shipyard is suspected of rigging its books to hide up to 1.5 trillion won in losses between 2013 and 2014.

The outcome of the probe by the Board of Audit and Inspection was based on an analysis of orders for 40 offshore plants won by the Korean shipbuilder over the cited period. Prosecutors are currently looking into some 500 orders clenched by Daewoo since 2006 and are known to have detected additional problems.

The company, along with two other major shipbuilders here, are currently undergoing self-created debt-restructuring plans in the face of a decrease in new orders caused by the protracted global economic slump. Prosecutors said Monday's questioning will be focused on Nam's personal corruption. (Yonhap)