NEW YORK, NY — City Comptroller Scott Stringer launched a wide-ranging investigation Monday into how city agencies handle reports of lead poisoning in children. The probe comes after city officials admitted to the New York Daily News that hundreds more kids living in public housing had tested positive for elevated lead levels than previously acknowledged.

"There is no question that someone or some agency is misleading the public," Stringer said at a news conference. The city Department of Health knew of 820 kids 5 years old or younger in New York City Housing Authority complexes who were found with 5 to 9 micrograms per deciliter of lead in their blood from 2012 through 2016, the New York Daily News reported Saturday.

That's despite claims from Mayor Bill de Blasio's administration that fewer than two dozen kids had elevated lead levels between 2010 and 2016. Stringer said his office would examine "policies and protocols concerning lead and children" across multiple city agencies, including the Department of Health, NYCHA and the Department of Housing Preservation and Development.

The investigation will examine practices not just for public housing but also certain private housing, shelters, daycare centers, parks and playgrounds, he said. "We want to create a trail to know exactly how the Department of Health — how they contacted parents and why they didn't contact other agencies, especially the New York City Public Housing Authority," Stringer said. "We also want to take this investigation a step further. What's happening in NYCHA could be happening in other buildings around the city."

Since 2012, the federal Centers for Disease Control and Prevention have reportedly recommended public health officials work to find possible sources of lead exposure when any kid age 5 or younger has a blood lead level of at least 5 micrograms per deciliter.

But the city reportedly used a threshold twice that for years. While the Department of Health has generally told parents when their children had lead levels of 5 to 9 micrograms, it only notified NYCHA and inspected apartments when kids were found with at least 10 micrograms, according to the Daily News.

The city didn't switch to the 5-microgram standard until January after federal housing officials began encouraging its use, the Daily News reported. Exposure to lead can cause brain damage, slowed development and problems with learning, behavior, hearing and speech, according to the CDC.