(JTA) – KIPP, one of the largest charter school chains in the country, dismissed its co-founder, Michael Feinberg, over claims that he sexually abused a student.

Feinberg was let go after an investigation found credible a claim of the alleged abuse some two decades ago, KIPP’s management wrote in a letter that The New York Times reported was sent to the school community on Thursday, Feb. 22. He was accused last spring of sexually abusing a minor female student in Houston in the late 1990s, a source told The Times. Feinberg denies the accusation, his lawyer, Christopher Tritico, told The Times. Investigators also uncovered evidence that Feinberg had sexually harassed two KIPP employees, according to the report. One case, in 2004, led to a financial settlement, the letter said, and the other could not be corroborated because the woman involved would not cooperate. Feinberg had never been told of the precise allegations against him, and had not been given a chance to defend himself, his lawyer told The Times.

Feinberg and David Levin, two former Teach for America teachers, launched KIPP in Texas in 1994. Today it counts nearly 90,000 students and 209 schools in 20 states. In 2008 they received the Presidential Citizens Medal from President George W. Bush. Feinberg and Levin, who are Jewish, also received the 2009 Charles Bronfman Prize. Established in honor of the Jewish philanthropist, the prize recognizes those whose humanitarian work and Jewish values combine to significantly improve the world. In 2008, Feinberg visited Israel to promote the KIPP concept. Israel currently has two schools inspired by the KIPP model.