Yonkers' inspector general launched an investigation Monday after the release of an undercover video that alleges corruption by teachers union officials.

Brendan McGrath, the city's inspector general, opened the probe after James O'Keefe, a conservative activist behind other undercover videos -- like the one that targeted Planned Parenthood -- posed as a Yonkers teacher who had assaulted a child and then took an unapproved two-week vacation.

In a 17-minute video O'Keefe posted online, Pat Puleo, president of the Yonkers Federation of Teachers, and another official appear talk to O'Keefe about the "wrongdoing."

As News 12 has previously reported, Puleo says the video is nothing more than a new example of O'Keefe's lying and deceptive tactics to try and take down organizations that disagree with his politics. The videos of Planned Parenthood employees allegedly selling fetal tissue led to congressional hearings and calls to defund the organization.

Depending on the outcome of the investigation, McGrath could recommend the union officials be suspended or let go.