The volunteer said Nora, 15, would have found it impossible to cross dense jungle - especially barefoot, the Mail reported.
“Nora couldn't have got there by herself,” the volunteer is reported to have said.
“Dense vegetation snags your feet. The average gradient of the slopes where Nora was found range from 20 to 40 per cent. You have to cross two reasonably deep streams to reach the area where she was found.”
He said his own boots were destroyed by the difficult terrain, including roots and rocks, adding: “I can't imagine how she could have walked to the place where she was found.”
The claims come as Nora’s family has called for an end to "unhelpful" comments attributed to them or those claiming to act on their behalf following the discovery of their daughter’s body on Tuesday, 1.6 miles from the holiday resort where they were staying.
Early on Saturday they issued a statement saying: "The family of Nora Quoirin would like to clarify several comments that have been attributed to the family or to people claiming to act on behalf of the family.
"They wish it to be made absolutely clear that the only comments and statements relating to the disappearance, death, investigation and any other matters that are actually from the family are those released via Matthew Searle of the Lucie Blackman Trust."
It added: "Any other comments and views are those of the speaker and do not necessarily reflect the views of the immediate family or an accurate portrayal of the facts."
The statement followed reports suggesting Nora's parents were considering asking for a second post mortem examination to be sure pathologists had not missed any evidence.
A first post mortem concluded that Nora starved after her disappearance and there was no evidence of abduction or kidnapping "for the time being".
After meeting Malaysia's deputy prime minister on Friday, her family said they are "struggling to understand the events of the last 10 days".
"The initial postmortem results have given some information that helps us to understand Nora's cause of death.
"But our beautiful innocent girl died in extremely complex circumstances and we are hoping that soon we will have more answers to our many questions."