The man travelling with an Australian backpacker until he disappeared in Brazil has vowed not to leave the country without his missing mate.
Rye Hunt was last seen leaving Rio airport on May 21.
CCTV footage from Galeao International Airport appears to show the 25-year-old and his travelling companion, Mitchell Sheppard, 22, arguing.
It's understood the pair then agreed to briefly separate to cool off.
Australian authorities say Mr Hunt subsequently left the airport alone in a taxi about 2.30pm.
His sister, Romany Brodribb, says Mr Sheppard - who remains in Rio - is committed to finding his friend.
"After Rye disappeared, Mitchell has been incredibly upset and worried and scared," she told ABC local radio on Monday.
"He has made the comment that he won't leave without Rye."
Mr Hunt hasn't used his social media, email and bank accounts since he disappeared.
It appears he hasn't used his phone either.
His camera, laptop and large backpack have been found by Brazilian police but it's unclear if his wallet, phone and passport have also been located.
The family haven't been told where his belongings were found.
"We are still yet to receive an update from DFAT (Australia's foreign affairs department) confirming the exact location where the effects were found," they said in a statement on Monday.
"The family are especially interested to know whether Rye's wallet, iPhone and passport were located among his effects."
Mr Hunt's uncle and girlfriend are flying to Brazil with the help of a crowdfunding campaign to join the search. Mr Sheppard's brother will also go to offer support.
Tasmanian and West Australian police have been working with DFAT and Brazilian authorities to find Mr Hunt. He grew up in Tasmania and had been working in Kalgoorlie until he left the country on April 1 to go travelling.
A social media campaign to #findrye has been shared across Australia and South America.
His family have thanked the public for the "love and support shown to his family at this difficult time".
