NEW YORK (CBSNewYork) — Mayor Bill de Blasio said Monday that he will no longer talk about a widening federal corruption investigation that stretches from the NYPD to his own fundraising.

As CBS2 Political Reporter Marcia Kramer reported, de Blasio has taken a vow of silence about the sprawling and complicated municipal corruption probe that has so far forced police Commissioner Bill Bratton to take action against five NYPD officials – four of them top commanders.

“I’m happy to take questions today, but not going to be speaking about this after today,” de Blasio said.

The probe is also looking aggressively at how team de Blasio staff raised funds for its various initiatives.

Kramer: “Mr. Mayor, there’s been a steady drip, drip, drip of stories about this for the past week. I wonder if there’s something you’d like to say today to New Yorkers about the integrity of your administration.”

De Blasio: “I hold myself and my administration to the highest standard of integrity. We are very, very careful about doing things in a legal and appropriate manner. We’re very, very careful about disclosing the support we get. We disclose everything, and we welcome questions about it.”

The mayor said his campaign did nothing wrong and has not been notified about any investigation, 1010 WINS’ Al Jones reported.

The FBI and the U.S. Attorney’s office have been asking questions as part of a probe centered on two businessmen with ties to the mayor’s campaign. Jeremy Reichberg and Jona Rechnitz both served on de Blasio’s inaugural committee and either donated or raised money for him.

De Blasio on Monday downplayed his relationship with Reichberg and Rechnitz, WCBS 880’s Rich Lamb reported.

“In terms of these two individuals, as I’ve said, I met them around the time of the general election; had not known them previously,” de Blasio said. “I have spent very little time with them in the scheme of things, and not much at all in the last year.”

As CBS2 first reported, federal investigators have been questioning members of the real estate industry about donations solicited by team de Blasio – including the actions of former campaign treasurer Ross Offinger.

As the feds’ pay-to-play investigation proceeds, there is new information about one of those under the microscope – former NYPD Chief of Department Philip Banks. Financial disclosure filed by Banks with the Conflicts of Interest Board showed that while he was still with the department, he claimed a payment of between $250,000 and $500,000 from JSR Capital.

JSR Capital is Rechnitz’s firm. The money was from an investment that Banks made with the businessman.

Banks’ attorney said the payout was legal and above board.

“Not one single dollar earned by Mr. Banks while a member of the PD or subsequent to his retirement, is any way related to illegal or corrupt activities,” said attorney Benjamin Brafman.

On the NYPD front, Bratton said Monday that he has not ruled out taking additional action — even though four top commanders have been removed from their posts, and a detective lost his gun and badge for taking the Fifth Amendment.

“The investigation is ongoing, so we just have to see where it goes,” Bratton said.

Banks’ financial disclosure forms show he has hundreds of dollars in other investments – mutual funds, an IRA, and a deferred compensation plan.