The body of an elderly woman was found inside a box inside her Brooklyn apartment Friday — and her son was taken into custody after allegedly admitting he hit her, police and law enforcement sources said.

A social worker made the grisly discovery while making a home visit around 12:15 p.m. at a Linden Boulevard apartment off Rogers Avenue in East Flatbush, according to cops and the sources.

The 67-year-old woman was found dead “in a box,” the NYPD said.

The son — who suffers from schizophrenia — allegedly admitted to hitting his mother and was taken into custody, according to sources.

The cause of the woman’s death has not yet been determined.