A Melbourne woman who said she was falsely incarcerated in Hawaii while trying to visit her American boyfriend for almost three months said she felt dehumanised during the ordeal.

Molly Hill, 26, said she was trying to visit her boyfriend Ross Maidl for an 88-day holiday when she was detained at Honolulu Airport by authorities who claimed she was trying to illegally immigrate to the US.

She had a 90-day tourist visa and had pre-booked return flights.

“I was in shock… I was in an interview room from 9.30am until 4.30pm,” Ms Hill told 9NEWS.

“I was told to stand completely naked, they went through my hair, I showed them the soles of my feet and my mouth and then they asked me to squat and cough.

“It was extremely violating. It happened within five minutes of arriving, I was struggling to understand what was happening to me.”

Molly Hill says she was handcuffed and placed in a women's prison. (Facebook)

She said they used preparations she’d made prior to leaving Australia as evidence she wasn’t planning to return.

“They were going through my diary and highlighting things. I thought it was astounding. I was trying to be organised by cancelling my electricity, having going away drinks for my birthday,” she said.

“They were using this as evidence that I was planning to leave and never come back despite also writing in the date of my return flight.”

Ms Hill was fingerprinted and eventually told she would not be able to enter the country and would need to spend a night the Federal Detention Centre in Honolulu until flights could be arranged.

She was unable to contact her boyfriend, friends or family and was detained in a cell with a single bunk bed and a toilet with another woman.

She was given a brown paper bag with an apple and a sandwich.

Ms Hill and her American boyfriend Ross Maidl. (Facebook)

“I was thrown into an exact communal prison environment,” she said.

“It felt so surreal.”

The next morning – which happened to be Ms Hill’s birthday - she was forced to undergo a second screening before being released from the prison and taken back to Honolulu Airport in handcuffs.

She was told she could return home and was forced to purchase a $620 flight home to Sydney.

“I can’t fathom how that is normal process. To put someone going on a holiday, to say the correct place for them to spend the night is a women’s prison,” Ms Hill said.

Ms Hill’s boyfriend had waited four hours for her and was told little information about his girlfriend’s whereabouts.

Her mother Donna Bridges said she didn’t understand the gravity of the situation until she received the first phone call.

“She told me she was in handcuffs… As a mum it’s your worst fear that your child has been violated in that way,” she said.

A spokeswoman for the Department of Foreign Affairs and Trade confirmed it assisted an Australian woman in the US yesterday.

“The Department of Foreign Affairs and Trade provided assistance to an Australian woman deported from the United States. Due to our privacy obligations, we will not be making any further comment,” the spokeswoman told 9news.com.au.

The US Customs and Border Protection said their initial investigation showed "US offices acted according to current laws and regulations".