This article was produced in partnership with Spotlight PA and The Philadelphia Inquirer, which is a member of the ProPublica Local Reporting Network.

For over a year, lawyer Bob Heist, then-chairman of the Milton Hershey School’s board, says he sought internal financial records detailing the spending history of the $17 billion charity, which has a mission to educate low-income students for free.

He now says he is being denied records he needs as a board member charged with overseeing the Pennsylvania boarding school’s operations, and earlier this month he sued the school to obtain the documents. It’s an extremely unusual step for a sitting board member, taken against an extremely unusual institution: The Milton Hershey School is the wealthiest pre-college educational institution in the United States. It controls 80% of the Hershey Co. candy giant’s voting shares, and reaps profits from the sale of Hershey chocolate bars, Reese’s peanut butter cups and SkinnyPop-brand snacks sold in thousand of U.S. retail stores.

The dispute is the latest in a series of legal entanglements involving the nonprofit Milton Hershey School and the members of its governing board. Two previous financial controversies raised questions about whether the school’s spending was serving the needs of its roughly 2,100 students, as required by law and enforced by the state attorney general’s office.

The suit also raises anew questions about board oversight of the vast Milton Hershey fortune, donated by the candy company’s founder to help poor and at-risk children. For months, The Inquirer, Spotlight PA and ProPublica have investigated this and other issues, including whether school leaders and board members have fulfilled that mission to a degree commensurate with the charity’s vast resources. The publications will share their findings in upcoming stories.

For years, critics have argued that the school, and the endowment that funds it, could be spending hundreds of millions more than it does. Because of Milton Hershey’s restrictive deed on the endowment, the charity cannot dip into any of its principal, now worth $16 billion. (That’s roughly the size of the endowment of the University of Pennsylvania, which is not subject to those constraints.) It can spend the income earned from those holdings, but it only spends part of that each year and has amassed about $1 billion in unspent income. The school recently received court approval to use some of those funds to build and run six preschool centers around the state that, in five years, will serve 900 impoverished children, a potentially significant expansion of its mission.

By far the nation’s richest private school, Milton Hershey currently spends about $139,000 per child each year in total costs. The residential school vigorously screens its applicants, and it offers rigorous academics as well as medical, dental and social services to students, many of whose families are below the federal poverty line.

A spokesperson for the school, Lisa Scullin, said in a statement that it has provided Heist with “extensive financial information and will continue to respond to any reasonable requests in his capacity as a board member.”

Heist said in the suit that the financial information provided didn’t include everything he was asking for and contained inconsistencies. Ricardo Meza, Heist’s lawyer and a former federal prosecutor in the Chicago area, said, “We are going to let the complaint speak for itself.”

Heist, who lives in Chicago and is a Hershey graduate himself, said he needed the records to ensure that school funds were not being “wasted,” to find out whether the school reported accurate information to the IRS, and to determine if consultants “exerted undue influence in order to receive funds.”

A spokesperson for Pennsylvania Attorney General Josh Shapiro, when asked whether the office plans to look into the issues raised by Heist, said the office had been “made aware of the petition and will monitor it, as we do with all legal filings against charitable entities across the Commonwealth.”