Belgian Prince Laurent, King Albert II's youngest son, appeared at a court of the central city of Hasselt on Tuesday as a witness in a fraud trial.
This is the first time that a Belgian royal family member has appeared at a civil court as a witness.
The trial, which started on Monday, involves 12 people accused of pocketing some 2.2 million euros (2.9 million U.S. dollars) allegedly siphoned from the navy budget.
However, several of the defendants have alleged that 43-year-old Prince Laurent knew that 175,000 euros (231,770 dollars) of the money was used to refurbish his home on the outskirts of Brussels in the 1990s.
The prince arrived with his lawyer and a police guard, amid much media attention at the courthouse in Hasselt, 80 km east of Brussels.
Although the Belgian king has legal immunity, Laurent does not.
Prosecutors, however, have not charged the prince with any wrongdoing, saying he was not directly involved in the scandal.
Laurent's lawyer, Fred Erdman, confirmed reports that Laurent was also questioned by police late Monday at the request of the prosecutor presiding over the trial.
By press time, it was still unclear whether he would testify in court.
The scandal has caused a political storm in the country. Opposition leaders last month urged the prince to explain his alleged role in the case. Several cabinet ministers have called for a review of the government's payments to the royal family. They also want the government to reconsider whether Laurent should continue to receive a yearly stipend to pay for his household.
Source: Xinhua