A 68-year-old Brooklyn man was taken into police custody Wednesday after a passerby caught him trying to load a tarp-covered dead body into a U-Haul, police sources said.

The good Samaritan was walking in Flatbush just before 4 a.m. when he spotted something wrapped in a tarp at 550 E. 21st Street, sources said.

Unsure what it was, the man kicked the tarp and checked underneath — but fled to call cops when he realized it was the body of a woman, according to sources.

A few moments later, another man was caught on camera dragging the body and loading it into a U-Haul truck, the sources said.

Cops arrived before the unidentified second man, 68, could take off, sources said.

EMS responded and pronounced the woman dead at the scene, cops said.

The 68-year-old was taken into custody on pending charges, police said.