Since then, his immediate family and the Uruti community have continued the search.
A Whanganui friend, who wished not to be named, said the family are extremely worried and Roberts' father has been out for hours every day in hope he will find his son.
A Givealittle page was made by the Uruti Interest Group for the Roberts family to continue the search.
Since the page was created, on August 8, 67 donations have been made and a total of $8765 has been raised.
Uruti Interest Group said on the page they wanted to give people an opportunity to donate to help pay for a helicopter to continue searching.
The friend said Roberts loved hunting and had survived in the bush before for a few weeks at a time but he always went prepared for the change of weather and with survival equipment.
"We're all grabbing at straws really - no one really knows what happened."
The friend said the family have been very humbled and grateful for all the donations.
"Whether people know Karl and the family personally or not at all, to put their hands in their pockets to help, I'm sure, is very humbling."
To make a donation or to keep an eye on any updates visit:
https://givealittle.co.nz/cause/findkarlroberts