Adelaide woman faces 25 years in Colombian prison over drug trafficking charges.

A 22-year-old Adelaide woman faces up to 25 years in a Colombian prison, after she was allegedly found with 5.8kg of cocaine in her luggage.

Cassie Sainsbury, a personal trainer from Moana, had arrived in Colombia on April 3 for a working holiday. Eight days later she was at an airport in Bogota, waiting to board her flight home, when she was arrested on drug trafficking charges.

Sainsbury, who is getting married in February, is currently detained in El Buen Pastor — a notorious women’s jail — and has been denied bail.

Sainsbury claims innocence, reportedly saying the drugs were hidden inside gifts she’d bought for her bridal party.

Her family is adamant she was set up by a man who had been “showing her around” during her trip. Her sister Khala Sainsbury told The Advertiser the man had given her a package he said contained 15 pairs of headphones.

“She came across some headphones that she was going to buy and pass out to everybody and he told her he knew a guy that could get them cheaper,” her sister Khala Sainsbury told The Advertiser.

“She did that and got them handed to her Wednesday morning before she left, she just put them straight into her suitcase.”

Sainsbury faces a maximum sentence of 25 years in jail.

“Our hearts break, because we know she is innocent, but stands little chance of proving it in such a corrupt country. We are currently facing expensive legal fees, and trying to support Cassie as much as we can, but is hard as we have little money,” Khala wrote on a crowdfunding page aiming to raise $15,000 to assist with legal fees.

"Cassie was planning her upcoming wedding to the love of her life, she has her full life ahead of her, and now it's all put on the line because of this."

Speaking with Channel Seven News, Sainbury's mother Lisa shared her distress.

“She’s caught up on the other side of the world for something she didn’t do, with no support over there, no nothing,” she said.