Arbon, 75, has been missing since he set out on a walk up Mt Davy to Mt Sewell near Greymouth last Wednesday.
He was captured on camera riding from Runanga to the Mt Davy area.
A police spokesperson said Arbon's bike was found on a nearby trail and search teams were out again despite poor weather in the area.
"Our teams remain committed to the ongoing search," they said.
"Roy's red bike was located on Rewanui Road and we continue to ask anyone for sightings of Roy the morning of 23 July. He was heading from Runanga to the Mt Davy area on his bike."
Arbon has a storied past including helping to recover bodies following the Erebus air disaster in Antarctica in 1979 and the bodies of people killed at Cave Creek in 1995.
He was later acquitted of cocaine smuggling charges in Western Australia after falling prey to an international drug scam.
Anyone with information that could help police is asked to contact them via the 105 service, referencing file 250725/2139.
