The family of a 22-year-old Australian woman accused of trying to smuggle cocaine out of Colombia are being told to 'get their story straight' after several discrepancies emerged in their claims about why she was there.

Cassandra Sainsbury was detained at El Dorado International Airport in Bogotá just as she was about to fly back to Australia on April 11, after she was found with 5.8 kilograms of cocaine hidden in headphones.

The young woman's family faced the media asking for donations to help her fight the charges, claiming she was a personal trainer in the country on a working holiday.

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Australian woman Cassandra Sainsbury, 22, faces 25 years in jail after she was arrested with 5.8 kilograms of cocaine at an airport in Colombia

The woman (pictured with her fiance) was detained on April 11 at Bogotá Airport just as she was about to fly back to Australia after a working holiday

However, Australia and Colombia do not have a working holiday agreement, and Ms Sainsbury's fiance Scott Broadbridge, has revealed she hasn't worked as a personal trainer this year.

Khala said her sister was tricked into being a drug mule by a man she just met who handed her a package containing the concealed drugs

'Although Cassie is a PT, she is not currently personal training and hasn't been for 6 months. I don't know why that was mentioned at all,' Mr Broadbridge wrote online.

'She helped manage a commercial cleaning business that had both national and international clients.'

The woman's sister, Khala Sainsbury, set up a fundraising page to help her sister with legal costs. On the page she wrote that her sister is a volunteer firefighter with Country Fire Service in Adelaide, but the organisation has said she hasn't worked with them for three years.

'Hi Khala, although SA Country Fire Service appreciate you helping your sister through this, we are concerned you are stating that she is a member of SA Country Fire Service,' Alison Martin a senior publicity officer wrote on the fundraiser page.

'She has not been a volunteer for the past three years and we would appreciate you taking all material relating to CFS from this profile.'

The page has raised $2,995 in four days but most of the comments appear to be negative towards the 22-year-old.

Khala said her sister (pictured) found a Colombian lawyer but he suggested pleading guilty to lesser charges to avoid an up to 25-year jail sentence

A message on the fundraising site from her fiance

Her mother, Lisa Evans, has maintained her daughter is innocent, saying she had been 'naive' in trusting a Colombian man to help her get a good deal on headphones

The young woman's family told Daily Mail Australia she thought the parcel contained headphones for her bridal party and friends back home.

However Bogotá residents, where she was caught with the drugs, say technology is expensive in Colombia – and headphones would be hard to find in the city.

'Colombia is not a country like Thailand where they have headphones in the market places like Dr. Dre Beats,' an Australian in Colombia said.

'Technology is considered expensive to buy here.'

The woman who claimed to have spent 'a lot of time in Bogotá' said she had never seen headphones for sale there.

Khala said her sister (pictured) found a Colombian lawyer but he suggested pleading guilty to lesser charges to avoid an up to 25-year jail sentence

Her family says she is innocent and being 'set up'

Khala said her sister was tricked into being a drug mule by a man she just met who handed her a package containing the concealed drugs

Mr Broadbridge at a music festival, the woman's fiance claims she was a manager of a cleaning business

Many people also questioned the difference in weight between the earphones and the drug parcel.

'Everyone knows that a extra 6kgs in headphones wouldn't feel right,' one person said.

'Always check your packages before putting them in your bag,' said another

Her family says she is innocent and being 'set up'

The family's fundraising page also claimed the Colombian government 'is corrupt' which has seen them receive angry comments from those who live there.

‘Don't call my country corrupt when she was caught with the good in her bag. You have lied twice in your fundraising intro,’ Ern Perez said.

‘Why are you lying, and it seems your family is trying to put sympathy to the Australian public in making false statements.’

Ms Sainsbury was an aspiring model before leaving for the South American country and had built her own starnow profile which invited potential client to view her Instagram account.

Working holiday visas to Colombia are only issued to citizen of France who are aged 18-30 and

The references to the firefighting service remain in the public cry for help.

Cassandra was planning a wedding to her fiance and 'love of her life' Scott Broadbridge (L) after they got engaged in October on a cruise to Vanuatu and New Caledonia

'She is just so scared that she is caught up on the other side of the world for something she didn't do with no support over there, no nothing,' Ms Evans told the Today Show.

The Adelaide woman was denied bail and is being held at the El Buen Pastor prison, which houses over 50,000 women.

Ms Evans said Ms Sainsbury's Colombian lawyer, who used to be the Mayor of Bogota, has advised the young woman plead guilty to avoid 25 years behind bars at her hearing in two months.

She said the 'best case scenario' is a minimum six-year sentence with a guilty plea.

'If Cassie gives information about the person that gave her the package it may come down a bit to four,' Ms Evans told KIIS 1065's Kyle & Jackie O on Monday.

The distraught mother said her daughter told her she had trusted a Colombian man who offered to be her translator and find gifts for her family.

'She mentioned these headphones she wanted to get and this man said 'I know a guy and if you buy 16 or 18 of them he can give you a really good price',' Ms Evans said.

'The day of her departure he gave her the package wrapped in black plastic and she put it in her luggage'.

The former personal trainer from Adelaide was denied bail and is being held at the overcrowded El Buen Pastor women's prison (pictured) until her hearing in two months

Ms Sainsbury's older sister Khala was to pick her up from the airport on Easter Saturday and didn't realise Cassandra's predicament until the morning of Good Friday.

'The trip was at least in part to promote her personal training business,' her sister told Daily Mail Australia.

The mother-of-four insisted her CFS volunteer sister was innocent and being 'set up'.

'Anyone that knows her, would say she is a kind, loving, happy kind of girl. She would help anyone out in need,' she said.

'Our hearts break, because we know she is innocent, but stands little chance of proving it in such a corrupt country.'

Her arrest came while Cassandra was planning a wedding next February to her fiance and 'love of her life' Scott Broadbridge, 23.

They got engaged in October on a cruise to Vanuatu and New Caledonia and have dated for just over 18 months.

'I'm devastated that my little girl is in this place. I'm scared to death for her. Our family just wants her home safe,' her mother Lisa Evans (L) said

The cocaine was concealed in the packing of more than 15 headphones Ms Sainsbury said she was given the morning of her flight home.

'It came to her already packaged and concealed and she put it straight in her suitcase. She's very naïve,' Khala told 9 News.

Cassandra grew up on the Yorke Peninsula before moving to Adelaide and has three huskies Buster, Bella and Rex living with her and Mr Broadbridge.

'She has her full life ahead of her, and now its all put on the line because of this. We miss her so much, and since we have very little contact with her its very hard,' her sister said.

The Department of Foreign Affairs and Trade said it was providing assistance to an Australian woman arrested in Colombia in accordance with the Consular Services Charter.

'Due to our privacy obligations, we are unable to release further information,' it said.

Prison inmates are searched in the El Buen Pastor women's prison at Bogota