As detectives launched a murder inquiry, attempts were being made to recover the body from the lip of a 100ft cliff face at Barn Hill Quarry, Chipping Sodbury, near Bristol.
Detective Superintendent John Newman said that the parents of the 18- year-old, who had been missing since leaving a disco early on Christmas morning, had been warned of the discovery.
Two schoolboys found the body on Saturday afternoon while they were playing at gravel pits which run alongside the half-mile-long disused quarry.
The woman was naked and her body apparently decomposed and disturbed by foxes. It was concealed in a "hide" formed from branches and trees and perched on the quarry edge in scrubland. Det Supt Newman could not say whether there were any apparent injuries or whether she had been sexually assaulted.
"The cause of death is not yet known," he said. He added that the quarry had been part of police search activity in recent weeks but that search had never been completed. As the area was particularly dangerous, police officers were now preparing to use ropes and harnesses to recover the body. A post-mortem examination was due to take place last night.
Louise's parents, Robert, 49, and Gillian, 48, were said to be "distraught" after being told of the find. They and their son Richard, 20, who was at the disco, have been comforted at their home by friends and relatives since her disappearance. Louise's Christmas presents are still unopened in her room.
"We have told them there is a probability from the features of the find that this is their daughter, Louise. We cannot, of course, confirm that until we have recovered the body," Det Supt Newman said.
The teenage clerical assistant vanished early on Christmas morning after she turned down friends' offer of a taxi lift home after a party at the Spirals nightclub, in Yate - just over a mile from the quarry. She was thought to have set off for her home at Chipping Sodbury some 10 minutes away.
Police have so far questioned more than 2,000 people, including more than 200 people at the disco. They are concentrating on tracing six men seen in the area between 1.20am and 2.50am on Christmas morning. They have urged the men to come forward and help eliminate them from the inquiry.
Det Supt Newman said: "We are now treating this as a murder inquiry. We are appealing to anyone who saw anything suspicious at or near the quarry over the Christmas period to contact us. Somebody out there must know what happened to this young lady. Somebody may have come home in a distressed or upset condition, with their clothing perhaps dishevelled.
"I would ask those people if any of their loved ones came home in that sort of state to search their conscience and contact us and help us resolve what happened."Reuse content