The company that compiles the annual Best Colleges rankings said the University of Oklahoma inflated its "alumni giving data" for the past 20 years, CNN reported.
U.S. News & World Report, which publishes annual rankings for more than 11,500 schools, said Oklahoma would be listed unranked because of the false information, which the company said had been furnished since 1999.
The university originally said its two-year alumni giving rate was 14% but said the correct number was 9.7%, according to U.S. News & World Report.
According to its methodology, U.S. News & World Report calculates its rankings based on data provided by the universities, such as standardized test scores of students, graduation rates and class sizes.
Oklahoma was ranked 97th in the 2018 Best Colleges survey, CNN reported. It was the first time the school had been ranked among the nation's top 100 universities and colleges.
In a statement, Oklahoma officials said they discovered the "misreporting of donations" in 2018 and immediately informed U.S. News & World Report, CNN reported. The school then provided updated information, the cable network reported.
"We appreciate the work of U.S. News & World Report and continue to have pride in the top rankings of several of our programs including our Masters of Business Administration, online bachelor's and graduate programs, specifically in Criminal Justice, Nursing and programs for veterans," interim university president Joseph Harroz Jr. said in a statement. "Rest assured, our University has learned from this occurrence and is working toward the goal of achieving future rankings for 2020 and beyond that reflect OU's excellence and academic success."