Queensland police say a man who failed to return from a bushwalk on Saturday had few supplies with him.
There are grave fears for Ross Forbes, 32, who has not been seen since he set off for a walk in the Tuan State Forest, south of Maryborough, about 6am on Saturday (AEST).
An air and land search failed to find any trace of the man on Sunday. The land search resumed early on Monday.
Police say the search is difficult in thick forest.
"It is believed the missing person does not have any supplies to sustain him for an extended period," police say.
Mr Forbes is described as Caucasian in appearance, approximately 178cm tall with a slim build, brown hair and a full beard.