Scott Richards, an economic development adviser from Adelaide and a holder of both British and Australian citizenship, spent more than three weeks in custody at Al Murraqabat police station after publicly promoting the efforts of a US-run charity, telegraph.co.uk reported on Friday.
He has been living in United Arab of Emirates with his wife and two children.
The post he shared was a link to a crowd-funding campaign by the Zwan Family Charity to buy tarpaulins, blankets, warm clothes and sleeping bags for children at the Chahari Qambar refugee camp on the outskirts of Kabul, in Afghanistan, the report said.
Following his arrest on July 28, he was held for 22 days and then charged with fundraising without permission.
Laws introduced in 2015, forbids the operation of any charity not registered in the United Arab Emirates, as well as prohibits donations or advertising fundraising campaigns without prior written approval from the Islamic Affairs and Charitable Activities Department in Dubai.
Richards had only been able to change his clothes once every seven days while detained and had to pay for water, his mother Penelope Haberfield, was quoted as saying to the BBC.
"His wife is under extreme stress," Haberfield said, adding, "she can only take the clothes to him once a week. She takes him money so that he can buy water and extra food.
"She's worried for him, she's worried for herself because if she runs out of money, will she have to leave the country? She's frightened for her children," Haberfield revealed.
