In an interview on NY1, Mayor Bill de Blasio doubled down on his defense of his embattled correction commissioner. NY1's Grace Rauh filed the following report.

In the face of new allegations against the Department of Correction, the mayor is praising the agency's commissioner, Joseph Ponte.

"The most important thing is, does a commissioner do a good job? Is the department doing what it is supposed to be doing? Obviously, he has done a very good job and he's helped to change the culture on Rikers Island profoundly and make that department work a lot better," Bill de Blasio said. 

The city's Department of Investigation announced Monday that it found a top correction official and several others in the department spied on investigators probing the agency. The accusation comes a week and a half after the city's top investigator found the correction commissioner used his city car for frequent trips to Maine. City officials are prohibited from using their city vehicles for personal travel.

"Every single one of those people is going to pay back the city of New York and the taxpayers of New York. Let me make that very clear. Joe Ponte's going to do that this week," de Blasio said. "Then, there will be a process to determine if there is any further actions needed through the conflicts of interest board."

As for the deputy commissioner accused of listening in on phone conversations outside investigators were having with confidential informants, he was not fired, but the scope of his job was modified.

"Removed from that work, and he's been removed from that work," de Blasio said. "Our understanding, based on the information received so far, it was not necessarily a situation to remove him entirely from the agency or from public employment but remove him from work that involved that kind of judgement.

The Department of Correction runs Rikers Island, a massive jail known to be plagued by violence. The mayor recently committed to shutting it down within 10 years. He is, however, standing by his commissioner, despite this latest wave of problems uncovered at the correction department by the city's top investigator.