NEW YORK (AP) -- Two nieces and a nephew of the reclusive heiress of a Montana copper fortune are asking a Manhattan court to appoint a guardian to oversee the 104-year-old woman's personal and financial affairs. The petition filed Friday also asks the court to bar Huguette Clark's attorney Wallace Bock and certified public accountant Irving Kamsler from visiting her, presenting her any legal documents, signing anything on her behalf or selling any of her property to "prevent the risk of further improper influence" by Bock and Kamsler "for their personal benefit rather than the benefit of Ms. Clark." Clark has lived in New York hospitals for more than 20 years, and the petition said she currently lives at Beth Israel Hospital. The Manhattan district attorney's office is looking into how Clark is being cared for and how her finances are being handled, two people familiar with the probe told The Associated Press last month. Bock and Kamsler have not been accused of any crime MSNBC.com first reported the legal probe and the family members' petition, which asks a judge to appoint Fiduciary Trust Co. International as guardian. Clark was born in 1906 in Paris to then 67-year-old U.S. Sen. William A. Clark, of Montana, and a 28-year-old Michigan woman named Anna Eugenia La Chapelle. Years of mining copper in Montana made Clark the second-richest man in America, after the Rockefellers. Huguette Clark's fortune is believed worth half a billion dollars. The petition filed by Ian Devine and Carla Hall Friedman of New York and Karine Albert McCall of Washington, D.C., says they are descendants of three of William Clark's children from his first marriage and are among Huguette Clarke's closest living relatives. It argues that if a guardian isn't appointed, "Ms. Clark is likely to suffer personal and financial harm because she remains at risk from her purported fiduciaries, Bock and Kamsler."