Earlier this year, Mayor Bill de Blasio abruptly shut down his nonprofit group, the Campaign for One New York. NY1 has learned that the group was accepting thousands of dollars in donations from people who do business with the city, potentially violating a directive from the city's Conflicts of Interest Board. NY1's Courtney Gross filed the following report.

It was one of the first things Bill de Blasio did when he became mayor.

Eight days into his administration, he got a letter from the city's Conflicts of Interest Board, the agency overseeing ethical conduct for local elected officials. It granted the mayor approval to fundraise for his newly established nonprofit group that was pushing his agenda, the Campaign for One New York.

Of course, there was a catch. De Blasio could not solicit donations for that nonprofit from "anyone with a matter pending or about to be pending’" before the city. The letter went on to say quote: “It is the Board’s conclusion that, as applied to the mayor, the 'agency' referred to is the entire executive branch…”

So more than two years later, NY1 examined all of the donations to the Campaign for One New York, which is now the subject of a federal investigation. We found that at least 60 donations came from an entity that had business with the city, or a company that was directly lobbying the city or was a union with a city contract.

In some cases, action by the de Blasio adminsitration occurred within days or months of the donation. For instance, the city's health care workers' union SEIU Local 1199 gave $250,000 in March of 2014. Three months later, the union signed a new city contract.

Or take real estate. A developer won a variance to build a commerical and residential project on a skinny TriBeCa lot in June of 2015. Three days later, the company gave $10,000 to the Campaign for One New York.

"The Campaign for One New York has done some very good work supporting important progressive goals, and obviously they're reaching out as they need to get resources."

De Blasio administration officials contend that donations the nonprofit received from people with business before the city do not violate the Conflicts of Interest Board directive.

In a statement, Maya Wiley, the counsel to the mayor, says, "The COIB letter is clear.  It does not prohibit solicitations from people who do business with the City.  It only bars the solicitation of someone 'with a matter pending or about to be pending' before the City. There was a process in place to insure that this guidance was scrupulously followed."

Of course, the timeline in some cases says otherwise. For instance, the Hudson Companies gave a $5,000 donation in February of 2014. In September, it was selected by the city to build a new public library in Brooklyn.

Or take the 2015 Rock and Roll Marathon. In June of 2014, the organizers contributed to the Campaign for One New York. They then started lobbying the Parks Department. In November, the city said the race was a go.

The mayor has always said the nonprofit's fundraising activities were above board, something he argued as recently as Monday morning.

"We hold ourselves to a very high standard. In fact, we literally have a conflict of interest board, and if there is any question, you go to them and they define what it is you are allowed to do and not do," he said.