Princess Irina Walker, the daughter of the last king of Romania, was hobnobbing two years ago with European royalty in Bucharest to celebrate the 90th birthday of her regal father. On Friday, she and her husband, a former sheriff's deputy, appeared in federal court to face charges of running a cockfighting business on their ranch in rural Oregon. Both pleaded not guilty and were released pending trial. Government prosecutors say Irina and John Walker staged at least 10 cockfighting derbies between April 2012 and April 2013, netting up to US$2,000 a day. Blades were attached to the birds' legs, spectators were charged admission, and food and drink were sold, the indictment said. Prosecutors say 24 marijuana plants, 24 guns and a large amount of ammunition were found during this week's raid, although no charges have been filed. Irina Walker, 60, is the third daughter of former Romanian King Michael I. The 91-year-old is one of the few surviving heads of state from the second world war and was forced to abdicate by the communists in 1947. Sent into exile, he lived in Switzerland and worked as a commercial pilot and briefly as a chicken farmer. According to a statement on the royal family's website, King Michael expressed "deep sorrow" about Princess Irina being arrested and hoped that the American justice system and Oregon courts act as quickly as possible. He did not mention his son-in-law and added that he hoped the presumption of innocence would function. The Walkers have been charged with operating an illegal gambling business and conspiracy to violate the federal Animal Welfare Act. Each of the offences carries a maximum possible sentence of five years in prison and a fine of US$250,000. Federal prosecutors are seeking forfeiture of the ranch. Authorities arrested 16 other people in connection with the case. Correction: in an earlier version of the story a photo of John Wesley Walker, husband of Irina Walker, was incorrectly captioned as King Michael of Romania. The error was corrected at 10am August 21.