Jo Lernout and Pol Hauspie, co-founders of Lernout & Hauspie Speech Products, will be detained in jail for a month while an investigation into fraud and stock-price manipulation continues, the public prosecutor in Ieper said.

The co-founders were arrested last week and appeared before a court in Ieper on Monday, when the judge decided to keep them in custody for a month, Jean-Marie Coppens, the public prosecutor in Ieper, said. Hauspie is being held in Bruges, and Lernout is in a jail in Ieper. Lernout, which makes software that enables computers to understand vocal commands, is under bankruptcy protection in Belgium and the United States, and faces claims from creditors under Belgian law of about $500 million. The company discovered a cash shortfall at its Korean unit last year of around $100 million because of revenue being booked from bogus contracts. Philippe Bodson, the new chief executive hired in January to try to save the company, said Friday he is prepared to sell off most of the company's assets to pay creditors.