Local reports say police in the south east Asian nation are investigating whether the pair took over-the-counter medicines after falling ill.
Briton Natalie Seymour loved travelling, her family told newspapers.
'They made a decision to sleep it off but never woke up again, or that's what I hoped. And then they were found by, I don't know.
An autopsy hopes to determine how the women died.
'She told us everyday where she was going to be going and what she was going to be doing, she always really wanted to travel and just wanted a break from work'.
"It was definitely not murder because we did not find any marks or bruises on their bodies".
Natalie Seymour told her mother she "wasn't feeling well" via a text message.
The bunk beds where the backpackers were found dead with pills scattered on the ground. Source Department of Immigration
The officer said food poisoning leading to an overdose was the most likely cause of death, but no tests had been carried out on the food in the girls' stomachs.
A spokesperson for the Monkey Republic hostel told the Mail: "It seems they were very close friends who were travelling together". They arrived together and went around together.
The two women met a year ago in Bali and became instant friends Seymour's mother, Wendy, told the Mail.
'This is now in the hands of the police but there is nothing suspicious about their deaths.
"One of the staff saw them (the night before they were found dead) and asked if they were going to eat in the restaurant, but they said they weren't going to be eating".
Natalie Seymour, aged 22, has been found dead in a Cambodian hotel, where she had been staying while travelling in Southeast Asia.
A Foreign Office spokesman said: "We are supporting the family of a British woman who has died in Cambodia, and are in contact with the local authorities investigating her death".