Officers were told the man, believed to be aged in his 20s, fell at Wentworth Falls at around 2.15pm on Sunday.

Police were last night at the scene, but high winds stopped them from finding the man.

A witness told the ABC she had seen a group of friends gathered on some rocks.

''Then they went down to the next one and I knew something was going to happen,'' she said.

''We just saw them all panic and a 20-year-old boy fell over 100m down the waterfall.''

A NSW Police spokeswoman said the retrieval operation would resume on Monday morning. She said the man was a British tourist and was at the waterfall with friends.

"We don't know how he's come to fall off," the spokeswoman said.

The fall is the latest in a string of incidents in the area.

Last Friday, a man and his two grandsons were found alive after going missing while bushwalking near Lithgow, while a 32-year-old woman was left in a critical condition in hospital after falling from a 35 metre cliff near Mt Victoria last Wednesday.

Last Thursday, police issued a warning to bushwalkers after a man had to be rescued after trekking alone in the Blue Mountains carrying only potatoes and naan bread in his pack.