Williston, N.D. (AP) The leader of an oil-rich North Dakota American Indian nation is accused of using his position to benefit from business partners' lucrative oil field contracts on the Fort Berthold Indian Reservation. A report into the business dealings of Mandan, Hidatsa and Arikara Nation Chairman Tex Hall was presented by Dentons Law Firm to the tribes' elected body last month. The report was only made public Monday after tribal members protested for its release. The investigation found hall had private agreements with Blackstone, LLC while the firm was working for the tribes. It also alleges hall tried to get an energy company to pay him between $1.25 million and $1.6 million before he would permit their work to go ahead unmolested. Hall's office in a statement called the report a sham.