The University of Pennsylvania is keeping mum on the resignation of a dean of its graduate school, who duped the Ivy League school into believing he had a doctoral degree from Columbia University.

A report this week by the Philadelphia Inquirer raised questions about the pedigree of Doug Lynch, vice dean of the graduate school of education, who claimed to have received a master's degree and a doctorate from Columbia University in 2005 and 2007, respectively.

Neither of those claims is true, according to Columbia officials. Lynch did received a master's degree in 2010, and has entered -- but not yet completed -- the doctoral program.

But UPenn, having found out about the bogus claims earlier this year, decided to keep Lynch in a leadership role, school officials told the Inquirer. Lynch was kept on as an administrator after "appropriate sanctions" were enacted, according to the report.

"He mistakenly believed that it was complete," University of Pennsylvania graduate school spokeswoman Kat Stein told the newspaper, referring to his doctoral degree.

This week, however, after the report appeared in the Inquirer, officials immediately placed Lynch on leave "pending the outcome of an ongoing investigation."

Lynch then resigned.

Various UPenn university officials who spoke to the Philadelphia Inquirer about the situation refused to speak to ABC News today, including Stein, university president Amy Gutmann, and dean of the graduate school Andrew Porter. All three officials directed calls to the media relations department, which said in a statement that "the university now considers this matter closed."

Prior to working at the University of Pennsylvania, Lynch worked at New York University and the College Board, according to his biography on the University of Pennsylvania's website.

In a short biography written for a University of Pennsylvania event where he spoke, Lynch is described as being an economist by training, who also completed doctoral work in education evaluation (ASU), Political Theory (New School) and an MBA (NYU). The biography states that Lynch helped start one of the country's first charter schools, helped the company WorldCom "out of sanctions with the SEC," and worked with the FDNY after 9/11.

Officials at Columbia University would not comment on the process for receiving a doctorate, nor would they explain how the mistake could have been made.

Reached at home by phone today, Lynch declined to comment.