The four victims -- identified as Danielle Jacobson, 22; Steven Presley, 17; Dominic Davis, 17; and John Lajeunesse, 16 -- were found by a passerby Thursday on Renegade Mountain, CNN reported.
Authorities have not released the identity of the person being questioned in the case or say whether they were a suspect, but said the person was arrested on unrelated charges.
Law enforcement officials said the deaths are being treated as homicides, WATE-TV, Knoxville, reported Thursday.
Cumberland County officials said they received several tips about car from area residents.
"We owe it to the families to do the best job and bring everything to bare, and utilize every asset we have," Sheriff Butch Burgess said.
Burgess says the county sheriff's office had never dealt with a similar case and immediately called the Tennessee Bureau of Investigation.
Renegade Mountain Community Club is a former resort community that recently exited bankruptcy. The area around where the bodies were found had been a retirement resort, a ski resort and a golf club.
WATE said only about 12 residents live at Renegade Mountain now, and some were involved in a dispute with owners over payment for services such as security.
John Moore, president of the homeowners association, said the victims were found in an undeveloped area.