A porn star turned drug mule will spend four and a half years in an Australian jail after admitting she tried to smuggle 30 kilograms of cocaine into Sydney on a cruise ship to clear a $20,000 debt.

Isabelle Lagace, 29, arrived in Sydney on the Sea Princess in late August 2016, having boarded the ship in England before travelling to Ireland, the US, Bermuda, Colombia, Ecuador and Chile.

Australian Border Force officials found a suitcase containing about 30kg of cocaine in her shared cabin, later estimated to be worth up to $21.5 million.

Australian Border Force officials found a suitcase containing about 30kg of cocaine in Lagace's (pictured) shared cabin, later estimated to be worth up to $21.5 million

Lagace's cabin mate Melina Roberge (pictured) has pleaded not guilty and will face trial at a later date

Late last year, Lagace pleaded guilty to importing a commercial quantity of a border-controlled drug but claimed to have been given an ultimatum about clearing a $20,000 debt to an unnamed person.

She also claims she began to receive threats - although she refused to provide any details - and was told her debt would be cleared if she provided a bag to another passenger to be filled with a substance.

In evidence presented to the NSW District Court on Friday, Lagace took full responsibility for her actions.

'I have embarrassed my family, my friends, myself,' she said.

In evidence presented to the NSW District Court on Friday, Lagace (right) took full responsibility for her actions

'I have embarrassed my family, my friends, myself,' Isabelle Lagace (pictured right) said

Australian Border Force officials found a suitcase containing about 30kg of cocaine in her shared cabin, later estimated to be worth up to $21.5 million

'It pains me to know that my defining years of womanhood will be spent in prison halfway around the world.'

Judge Kate Traill said the defendant had a job, an apartment and a support network when she decided to go through with the plan.

'There were many choices open to her to pay the debt,' she told the court.

The judge also rejected as 'vague and imprecise' the woman's claims of a threat, noting she was non-responsive and evasive when asked to elaborate.

In evidence presented to the NSW District Court on Friday, Lagace (court sketch) took full responsibility for her actions

The alleged drug mule was pictured in Los Gemelos throwing her hands in the air with a friend

But Lagace had good prospects of rehabilitation and a solid support network, Judge Traill said.

She imposed a sentence of seven years and six months, however, after the non-parole period was backdated to her arrest date Lagace will likely be released in February 2021.

Lagace's said she was angry to have been involved with the 'dirty, filthy drug trade'.

'This will haunt me for the rest of my life.'