NEW YORK - A top donor to Mayor Bill de Blasio's 2013 campaign pled guilty this week to federal bribery charges.

Federal prosecutors began investigating Brooklyn real estate developer Jona Rechnitz last year.

They say he knowingly gave money to public officials in exchange for favors.

That includes giving the former head of the Correction Officer's union $60,000 for investing in a hedge fund.

Rechnitz gave tens of thousands of dollars to support de Blasio's mayoral bid and his now-defunct non-profit group.

He later started working with federal prosecutors on their investigation into the mayor's fundraising activities.

No criminal charges were ever brought against the mayor.