There is still no sign of an Air New Zealand pilot missing in Hong Kong since Wednesday.
The airline says the extensive search will continue on Monday if necessary.
Air New Zealand says more than 200 people resumed the search for Steve Morrissey on Sunday morning.
The 51-year-old pilot has not been seen since Wednesday, when he went walking with a colleague on the Wilson Trail in Hong Kong's New Territories hill area.
The airline says in an update to staff that abseiling specialists and tracker dogs are being used.
It also says boats and helicopters are also helping the search, which includes the village at the trail's end.
Mr Morrissey is said to be a fit and experienced tramper.