The search for an Air New Zealand pilot missing in Hong Kong may be called off today, seven days after he disappeared on a tramping trail.

First Officer Stephen John Morrissey was last seen on Wednesday while tramping with Captain Mark Apperley on the Wilson trail in Hong Kong's New Territories.

More than 120 people searched Pat Sin Leng Country Park and surrounding areas yesterday and police were still classing it as a search and rescue situation, Air New Zealand deputy chief executive Norm Thompson said.

He said reports the search was being scaled back were incorrect because many of the search and rescue volunteers who helped on the weekend had to return to their jobs on Monday.

Hong Kong police confirmed that they would continue the search at the same level today if needed, but there had been no new leads in the search after a hat found on the trail on Sunday was ruled out of the investigation.

Any speculation on what might have happened to Mr Morrissey was baseless and did not help the difficult situation that his family was already facing, Mr Thompson said.

A "very hot weather warning", issued after temperatures reached 34 degrees Celsius, was expected to affect the search.

Today was forecast to reach up to 33 degrees Celsius.