An alarming number of children in public housing have been poisoned by lead, and officials are claiming the de Blasio administration is covering it up.

"There is no question that someone or some agency is misleading the public," City Comptroller Scott Stringer said. "That's why we are launching this investigation."

The city comptroller announced he was opening up an investigation into the hundreds of children in public housing who had elevated blood lead levels. Up until this point, the de Blasio administration said there were very few.

"Between 2014 and 2016," Mayor Bill de Blasio said in November of 2017. "four children I NYCHA [New York City Housing Authority] tested positive for elevated lead levels."

But first reported by the Daily News this weekend, 820 kids under the age of six had elevated lead levels from 2012 through 2016.

On Monday, a top city councilman called for Deputy Mayor Herminia Palacio's resignation.

"The deputy mayor systematically misled the council and the public about the full extent of lead poisoning and lead exposure in public housing," Bronx City Councilman Ritchie Torres said. "She should resign."

• Herminia Palacio defends the city's response to children in NYCHA units exposed to lead

What the city was doing was disclosing figures regarding children who had a high blood lead level, but not mentioning those with a lower but still alarming level.

That level, specifically 5 to 9 micrograms micro-grams per deciliter of blood, still triggers federal health guidelines, including an environmental assessment to find out the source of the lead exposure.

Up until January, city officials would send a letter to the parents of these kids, not inspect their NYCHA apartments.

"For years, our Department of Health has been following up in each and every case when there is an elevated lead level in any child," de Blasio says.

The mayor called into NY1, before heading off on a week vacation on Monday, trying to silence the scandal. He announced this weekend that the city would now inspect all apartments for kids under the age of 18 if they have this lower blood lead level.

Speaking with NY1 by phone, the mayor said the 820 children claimed by the Daily News to have elevated lead levels in NYCHA housing only represent a fraction of cases in the city.

"What we've done in this city over the last decade is reduce the amount of elevated lead levels in kids by about 90 percent," de Blasio said. "We have the best public health department in the entire country, and they have aggressively followed up on each case for years, and they have published the data for years. What hasn't been done is to separate the NYCHA cases, which are clearly the absolute minority, a small percentage of the cases, they have not been published separately, we're going to be doing that from now on."

De Blasio said if there are any children that have not yet been tested, and their parent or guardian fear there may be a problem with lead, they can call 311 to set up a free screening.

After all of this, we should also note that NYCHA released a new list of all the projects it needs to get done to be in a state of good repair.

In the past five years, the cost has nearly doubled. It is now almost $32 billion.