Friends of British backpacker Amelia Bambridge have spoken of their anger at discovering images of her dead body circulating on social media.
Hannah Clark - who said she had to spend hours searching for the images to report them - said Instagram deemed a photo of the arm of the corpse not to have broken its guidelines.
The friends said photos were also sent via direct message to Amelia's sister.
Facebook said it removes graphic content "when we are made aware".
'Don't open your phone'
One of the photos of the 21-year-old - who a post-mortem examination concluded died from accidental drowning after going missing in Cambodia - appeared to show Ms Bambridge's body floating in the water.
"By the time I saw it it had thousands of comments, likes and shares," Ms Clark told the BBC's Victoria Derbyshire programme.
"My first call was to [Ms Bambridge's] sister Georgie to say, 'Don't open your phone'."
"I was just shocked beyond belief. It's disrespectful to Amelia, her family."
Ms Clark had not at that point received confirmation of her friend's death, believing the 21-year-old from Worthing in West Sussex still to be missing.
"To know thousands of people knew [she had died] and saw before you - who didn't know her - and were then sharing that... I was just so angry," she explained.
"I should have had time to come to terms with what happened. But instead I was immediately on my phone for 24 hours trying to search her name and see if there were any posts to get them reported and removed."
Ms Clark said some images on Facebook - which owns Instagram - were "removed after a few hours, but by that point we don't know who saved them".
Since then, more posts have begun circulating containing those same images.
Ms Clark said she had tried to find someone senior at Facebook to contact, but it proved "impossible".
Temisis Conway said she had seen the images "time and time again", in an attempt to protect Ms Bambridge's family from viewing them.
She said the photos had been sent via direct message to her and Ms Bambridge's sister.
Ms Conway added that she was "gobsmacked" to be told by Instagram that an image taken of the arm of Ms Bambridge's corpse, which was posted on the platform, was not in breach of its guidelines.
"No-one wants to remember their best friend in that way," she said.
"She was my favourite person," said Ms Clark, remembering Ms Bambridge. "She is someone who will go out of her way for anyone."
Facebook said in a statement: "Amelia's death is heartbreaking, and our thoughts go out to her family and friends.
"We have clear rules against posting graphic content and when we are made aware of it, we remove it."
The UK Foreign Office said: "Our thoughts are with Amelia's family at this extremely sad time, and we continue to do all we can to support them.
"Our staff in Cambodia and in the UK are providing bereavement advice and emotional support, and remain in close contact with the Cambodian authorities."