A body has been found in the search for teenage hiker Lily Hooper, who disappeared eight days ago.

The tragic discovery was made about 11.30am on Thursday morning following an extensive search of the NSW Southern Highlands.

“While yet to be formally identified, the body is believed to be that of the 18-year-old woman,” police said.

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Police initially told media the 18-year-old had been found alive; however it was later confirmed she had died.

NSW Premier Chris Minns had also announced that Hooper had been “found alive”, saying she had been located in the bush with “half a bottle of water with her”, before correcting the statement a short time later.

“I’ve got some terrible news,” Minns said.

“I apologise to the committee, but it seems as if the early advice was wrong.

“Lily’s body’s been found and she’s been found deceased.

“I only raise that because I made the earlier advice and I’m very sorry for that.

“This is obviously devastating and I’m just profoundly sad for her family and all those concerned.”

A body was found on Thursday. Credit: 7NEWS

Hooper left her home on Burragorang Rd in Oakdale about 8am on August 12 to go hiking in Nattai National Park, in the NSW Southern Highlands, but had not been seen since.

Police previously said Hooper had been texting her family about the hike but failed to return home by 10pm that day, which was “well overdue from her anticipated completion time”.

Her car was found about 11pm that night at the beginning of the Bonnum Pic walking trail on Wanganderry Rd.

Her disappearance sparked a major search and rescue operation involving police, emergency services and the Australian Army.

Her family had remained hopeful since her disappearance, describing her as a “tough girl”.

In a statement on Monday, the family thanked the community, emergency services and volunteers for their support.

“Our family is absolutely devastated that our beloved daughter Lily is missing,” the statement read.

“We would like to thank all the emergency services and volunteers for their support and continued commitment to the search, not only during the day but throughout the night.”