Mayor Bill de Blasio on Thursday morning chastised reporters and editorial boards who have accused him of “hiding behind lawyers” — as an interviewer phrased it — in the latest case of alleged fatal child abuse, saying his critics are “hiding behind this argument.”

The Manhattan district attorney is investigating last month’s death of Zymere Perkins, 6, of Harlem, who was allegedly regularly beaten — including with a broomstick — by his mother’s boyfriend. Since mid-2015, the New York City Administration for Children’s Services had responded five times to concerns about the child and the family.

At a Wednesday news conference in City Hall, the Democratic mayor would not answer reporters’ questions seeking details about where and how the system failed Zymere, referring queries to the city’s first assistant corporation counsel.

On Thursday, on his weekly segment on WNYC-FM’s “The Brian Lehrer Show,” de Blasio bristled at criticism that he was hiding behind his lawyer and hiding behind the fact that the case is under active investigation.

“We had exhaustive conversation about this yesterday,” de Blasio said Thursday. “And I would ask of people who are serious about getting to the truth: They should stop hiding behind this argument.”

De Blasio told Lehrer, “The word investigation suggests the formal gathering of the facts . . . That’s what the people deserve, not speculation, but a final accounting of the facts.”

He rebutted suggestions that he was not doing enough.

“We had all the appropriate leaders of the administration, including myself, taking full responsibility, announcing a whole set of reforms, talking about everything we’re going to do to continue proving that we can fix this system,” he said.

The mayor pointed out the various city agencies that were involved in one way or another in Zymere’s case, including the Administration for Children’s Services, the NYPD, the Department of Education and the Department of Homeless Services. He acknowledged that the system had failed Zymere and that more coordination and follow-through were needed.

Zymere’s death on Sept. 29 recalled other high-profile child endangerment cases in New York City, including that of 4-year-old Myls Dobson two years ago and Nixzmary Brown in 2006.

De Blasio’s spokesman Eric Phillips on Twitter also took issue with reporters who have said the mayor wasn’t being forthright.

Phillips tweeted that “hiding behind lawyers” is synonymous with “we just want newsier answers now rather than when appropriate.”