A source tells NY1 that Mayor Bill de Blasio is returning campaign donations given to him by a Brooklyn businessman at the center of the NYPD's alleged bribery scandal.

The source says the Mayor is giving back the nearly $10,000 donated to his mayoral campaign by real estate executive Jonah Rechnitz and his wife.

Rechnitz also donated $50,000 to the Mayor's now-defunct non-profit, the Campaign for One New York.

It's unclear whether that donation will be returned.

Rechnitz and another real estate executive are under federal investigation over accusations that they provided NYPD officers with money, vacations and even diamonds in exchange for police favors.

A source says the Mayor is unaware of any federal investigation into his campaign fundraising

A spokesman for the Mayor says quote:

"We are fully confident that the campaign has conducted itself legally and appropriately at all times."

Meanwhile, the New York Post cover story on Saturday says the FBI is looking at the mayor's campaign donations.