A newborn baby’s leg appears to have been found in the New York City sewer system, police sources said Wednesday.

The “possible human remains” were discovered by a city Department of Environmental Protection employee on a sewage conveyer belt Wednesday morning inside a Bronx facility, according to an internal report shared with The Post.

The remains appear to be a leg from the knee down, and a separate source told The Post it belongs to a baby.

The NYPD is waiting for confirmation from a medical examiner to determine if the remains are indeed human and belong to an infant, The Post was told.

The case is being investigated by the 41st Precinct in the Bronx.