Harvard University placed Nowak on paid academic leave on May 1, 2020 because of his affiliation with convicted sex offender Jeffrey Epstein. A report commissioned by the university found that Nowak had repeatedly requested access to Epstein's philanthropy following the latter's conviction but had been blocked by Harvard administrators. Nonetheless, Nowak allowed Epstein to visit the PED offices more than 40 times between 2010 and 2018 after his conviction, to maintain an office with a phone line and webpage, and to interact with students at PED, helping to rehabilitate Epstein's public image.