Human leg bones wash up in Philadelphia park

Two human leg bones have washed up in a Philadelphia park , sparking an investigation.

The macabre discovery was made at around 5pm on Sunday by a woman walking along the waterline of the Delaware River in Penn Treaty Park, Fishtown, the Philadelphia Police Department said.

The woman found what appeared to be human shin bones in a grassy, rocky area along the park's waterline and contacted law enforcement.

Police said the remains were later confirmed to be a human femur and tibia, or upper and lower leg bones.

At present, who the bones belonged to, when they died and how they died remains a mystery, with police saying it is not yet clear if a crime has taken place. However, police do believe the person has been dead for a long time.

Philadelphia Police Inspector D F Pace told 6ABC: "It is unclear, the identity of the individual, sex, age, race – none of that is clear from this."

No further evidence was found at the scene.

The medical examiner's office will now examine the remains further.