Rescuers have found the body of missing hiker Lily Hooper in a tragic end to the lengthy search.

Authorities found the body, which has not yet been formally identified but is believe to be Hooper, in bushland about 11.30am on Thursday, NSW Police said in a statement.

Earlier, NSW Premier Chris Minns reportedly interrupted budget estimates to share the “fantastic news” that the 18-year-old had been found alive after more than a week.

However, he later confirmed the sad reality that the Oakdale teen was dead.

“She has been found deceased, and I only raise that because I gave earlier advice,” Minns said.

“This is obviously devastating, and I am profoundly sad for the family and all those concerned.”

Hooper had been missing since last Wednesday, August 12, after embarking on a hike in the Nattai National Park in NSW’s Southern Highlands.

The Oakdale teen did not return that evening and could not be contacted on her mobile phone, triggering a wide-scale search.

Hundreds of emergency personnel, loved ones and volunteers battled unforgiving conditions across the weekend to no avail.

Detective Inspector Brendan Bernie said Hooper was an experienced bushwalker and they hoped that would get her through the ordeal.

But for more than a week searchers found no trace since they discovered her car at the Bonnum Pic trailhead last Wednesday night.

On Tuesday, Hooper’s family said they were “absolutely devastated that our beloved daughter Lily is missing”.

“We desperately want to bring Lily home safe and we ask as the search continues, to keep our family and Lily in your thoughts.”

The family thanked the emergency services and volunteers for their support and commitment to the search — “not only during the day but throughout the night”.

“We appreciate people who have made offers for the search but, due to the terrain and conditions, we ask just professional search teams continue,” they said.

“We also ask for privacy and understanding as our family navigates this unimaginable situation.”

The search included crews from NSW Police, the Rural Fire Service and the State Emergency Service.

Rescuers met with rugged, dense terrain at the national park and cold, wet and foggy weather.

Police also used a thermal imaging helicopter at night.

-with AAP