Catherine Shaw had been travelling in the central American country for two weeks.
The Lucie Blackman Trust, which is supporting Ms Shaw's family, said on Monday evening that a body had been found which is believed to be Ms Shaw's.
Guatemalan police said search teams have located a body at San Juan La Laguna.
Ms Shaw, from Witney, near Oxford, had been staying near Lake Atitlan, in the remote Sierra Madre, with a friend.
"If anybody has any information, at all, please contact us, the Lucie Blackman Trust, or the police", added her father. "Please respect their privacy at this hard time".
The hotel said Catherine had been recorded on CCTV leaving at 1.37am on Tuesday carrying a musical instrument.
The trust said that at this point she had a puppy with her but no other possessions.
The puppy was later found alone, shivering at the highest lookout of Indian Nose, a volcano overlooking Lake Atitlan, San Pedro and San Juan between 5am and 6am on Friday morning, the trust said.
He confirmed that all her belongings had been left behind, adding "Not knowing anything about Catherine, Elena returned to our hotel on Thursday afternoon asking after her and that was when Catherine's belongings were handed to her".
The trust has received many sightings of female travellers matching Ms Shaw's description, and it has become clear that there are at least three travellers similar to her hiking in the area.
She was very much a nature lover and adored sunrises, so it seems quite conceivable that she went up the mountain to greet the sunrise, shedding clothing as she went, and due to her lack of intake of food and fluid may have passed out or fallen, causing the wounds to her body.
Ms Shaw has been travelling since September and has been to Mexico and California.