A woman's partially burned and naked body was found Tuesday morning in an alleyway in West Philadelphia — and investigators believe she may have been killed by a man she met online.

The unidentified woman's remains were found around 10 a.m. on the 200 block of South 49th Street, police said, and two sources said it appeared as if she had been stabbed and burned before being covered with leaves behind an apartment building.

The sources said a man in his early 20s who lived in the building with his parents told them he had murdered the woman, and that his parents subsequently reported the crime to police. One source said the man had met the victim online.

Homicide Capt. John Ryan said Tuesday night that investigators were still sorting out many details about the crime, including how the woman — who was naked and partially burned — might have known her killer and how exactly she died.

A police spokeswoman said Tuesday night that a 24-year-old man was in custody in connection with the death but had not been charged.