An investigation that has led to the indictment of a jockey for conspiring to fix races is ongoing and may result in additional charges against other riders, the prosecuting attorney in the case said on Thursday. David Morris, the assistant U.S. attorney for the Eastern District of Michigan, declined to comment further on the investigation. "Whether anyone else is going to be charged remains to be seen," Morris said. "But that is a possibility." The indictment, released on Wednesday, charged jockey Ricardo Valdes with 19 counts of conspiracy to commit wire fraud, conspiracy to influence sporting events by bribery, and unlawful use of a facility in interstate commerce. Two Detroit-area businessmen, Ghazi Manni, 52, and Mitchell Karam, 76, were charged with identical counts. Efforts to locate Valdes were unsuccessful on Thursday. A native of Panama, Valdes last rode in a race in North America in November 2006, according to racing records. According to the indictment, Manni and Karam held discussions with Valdes "and other persons known or unknown to the grand jury" about races at Tampa Bay Downs. Valdes agreed to hold horses, the indictment states, and also attempted to recruit other riders to hold horses. Valdes was one of seven jockeys who were barred by Tampa Bay Downs late in 2006. The other jockeys were Derek Bell, Jorge Bracho, Luis Castillo, Jose Delgado, Terry Houghton, and Joe Judice. The indictment cites four specific races at Tampa Bay Downs in which Valdes rode, held between Jan. 10 and April 15, 2006. In three of the four races, Valdes's mount did not finish in the money, but in one, the third race on Jan. 29, 2006, Valdes's mount, the 4-1 third choice, finished second. The indictment states that Manni and Karam placed wagers on the races, but no amounts are given. Morris would not provide details about any specific bets or whether the bets were successful. Although the indictment includes references to Great Lakes Downs and Delaware Park, no races at the tracks are cited specifically. After the jockeys were barred at Tampa Bay Downs, a Jockeys' Guild official said that investigators had recently interviewed jockeys about a race at Great Lakes because of a large number of suspicious wagers cashed on it at Delaware Park. Manni and Karam were also named in a separate indictment released on Wednesday and charged with bribing basketball and football players at the University of Toledo from 2003 to 2006. Both indictments include extensive records of telephone calls obtained by federal wiretaps. Asked if the horse racing investigation arose from the wiretaps, Morris said that he could not comment, "but that's a good guess."