DALLAS -- Dallas County District Attorney Craig Watkins refused to appear in court Thursday to answer a complaint that his office is pursuing a criminal case against a member of a fabled Dallas family at the behest of a campaign donor.Watkins was called to court by attorneys for Al Hill III, one of many heirs to the Hunt oil fortune, who is charged with mortgage fraud. Hill's attorneys argue that Dallas attorney Lisa Blue consulted with Watkins repeatedly before the case went to a grand jury.Blue and Hill have been involved in a multimillion-dollar dispute over legal fees dating from Hill's long-running conflict with his family over his inheritance.Hill III is the oldest great-grandson of oil tycoon H.L. Hunt. His late grandmother, Margaret Hunt Hill, the oldest of Hunt's 14 children, was married to accountant Al Hill Sr. The Santiago Calatrava-designed suspension bridge over the Trinity River near downtown Dallas is named for her.Attorneys for Watkins said Thursday he has the right to decide what cases to prosecute. They accuse Hill's team of trying to get around a grand jury indictment and say that forcing Watkins to explain himself would set a bad precedent for future DAs.The hearing was eventually delayed until March 7.State District Judge Lena Levario at first declined to excuse Watkins from appearing in court, expressing frustration as prosecutors repeated their arguments unsuccessfully.Eventually, Levario told prosecutors, "We need to get Mr. Watkins down here."After a break, prosecutor Teresa Snelson told Levario that Watkins "is not going to make himself available.""It's his position that it would be improper for him to make an appearance in this matter and discuss issues that are clearly within the purview of his discretion as the district attorney," Snelson said.But she also said that although Watkins was in his office, he was ill and didn't feel well enough to testify -- the first time anyone had mentioned that Watkins was sick. Watkins' spokeswoman, Debbie Denmon, declined to give details about the illness."We think it's an important case for prosecutors throughout the state to be able to conduct their investigations in an unfettered way," Russell Wilson, the prosecutor representing Watkins, said afterward.Blue is a longtime donor to Democratic candidates and described herself in a court filing as a "personal and social friend" of Watkins.She represented Al Hill III in a long-running civil suit over his inheritance. The case was settled in 2010 for about $115 million, according to The Dallas Morning News. Afterward, Blue and two other attorneys took Hill to court in a dispute over legal fees from that settlement.Hill's current legal team argued in a court filing last year that Blue raised money for Watkins, spoke to him repeatedly and bragged about their close relationship."The D.A.'s Office has served as a stalking horse in this case for various interests, none of them the interest of justice," his lawyers said in a filing.Blue said in a court filing Tuesday that she took two phone calls from Watkins after she had finished representing Hill. She said Watkins began the calls with the word Hill or Hills, and in one conversation mentioned the word indict or indictment -- at which point she immediately stopped the conversation.But in court Thursday, she declined to answer questions, citing her Fifth Amendment right against self-incrimination.