Police have recovered the bodies of a British father and his son after five members of the same family were caught in a landslip in the NSW Blue Mountains.
"The bodies of 49-year-old man and a nine-year-old boy were retrieved with the assistance of PolAir about 9.30am," a NSW Police spokesperson told AAP on Tuesday.
They both died at Wentworth Pass following the incident, which was reported to emergency services about 1.40pm on Monday.
A 50-year-old woman and a 14-year-old boy were winched from the scene and taken to hospital with significant head and abdominal injuries following the landslip on the walking track.
They had undergone surgery but remained in a critical condition, police said.
A fifth family member, a 15-year-old girl, was treated for shock. She is under observation in hospital.
"This event has led to utter tragedy for visitors to our region," said Blue Mountains Mayor Mark Greenhill on his social media.
"All our thoughts are with those affected and all who love them."
Police said the people were British nationals who were holidaying in Australia.
NSW National Parks and Wildlife Service said the tourist site was closed as a safety assessment took place.
"Unfortunately it is not possible to predict and eliminate all natural risks such as rockslides, which can occasionally occur around the state," it said on Tuesday.
"The walking track where this incident occurred was inspected in the days before the rockslide as part of a routine track assessment program."
The landslip comes after recent heavy rain drenched the area, causing mudslides and flash flooding, as Sydney recorded its wettest March ever.
With significant rainfall predicted later in the week, the national park will remain closed.
Blue Mountains Area Command Detective John Nelson described the incident as "quite a tragic scene."
The 15-year-old girl was "extremely distressed", he said.
The "heartbreaking" incident happened in an "extremely dangerous, extremely unstable environment", NSW Ambulance Acting Chief Superintendent Stewart Clarke said.
NSW Police are working with the British consulate to contact relatives of the family.
AAP has contacted the British consulate for comment.
with PA