Cassandra Sainsbury is being “unfairly” pressured to plead guilty and accept a shorter sentence, even if she is innocent, according to an international law expert.

The 22-year-old from Adelaide was arrested for allegedly carrying 18 packages of cocaine, amounting to 5.8kg, at Bogota’s international airport on April 12.

Ms Sainsbury faces a maximum 25 years in a Colombian prison if found guilty, with the option of an early plea reducing it to a four-year term – perhaps serving two years in Bogata and the remaining two years in home detention in Australia, as her lawyer has suggested.

However, if she pleads not guilty she could be waiting “three to four years” for her trial to commence, which University of Newcastle international law expert Amy Maguire says violates basic human rights law.

“I see a real element of unfairness in the process as it’s running there at the moment,” Dr Maguire told The New Daily.

“One of the key elements of a fair trial in human rights law is that the trial be prompt, and the longer the wait the less fair the process is.

“There shouldn’t be such a delay in getting to the trial because that period of delay puts undue pressure on the accused to potentially take a guilty plea, just to have the certainty of getting out of prison after a certain period of time.

“That sort of process could well lead to wrongful conviction of innocent people.”

Inside one of Colombia’s most notorious women’s penitentiaries, El Buen Pastor. Photo: Moon Foundation

Colombian-based lawyer Orlando Herran, who visited Ms Sainsbury on Thursday, said she still had not decided if she will enter a guilty plea or not, The Advertiser reported.

Mr Herran advised his client to plead guilty in an attempt to lessen the sentence, a plea Dr Maguire said was common in situations like this.

“Certainly from a legal point of view I would say it’s definitely a possibility for her to plead guilty regardless of whether or not she is innocent,” she said.

“If you look at a situation like this it’s never clear-cut. Many reasonable, rational people would well decide to take a guilty plea in this type of situation because they feel too much pressure and uncertainty around what the alternative outcome could be.

“Even if she does plead guilty, that could be a strategic decision rather than conclusive evidence of her guilt.

“[If pleading innocent] you would need to be both convinced of your innocence and very confident of your capacity to demonstrate it in court.”

Cassie’s ‘grave problem’

A key measure in proving the South Australian’s innocence revolves around an unknown man who allegedly provided her the headphones filled with cocaine.

However, Mr Herran told Fairfax Media the man has proved to be a “ghost” and that “there’s no evidence of his true identity”.

“Cassandra says that a person she knew only by one name, and that name was Angelo or Tom, had offered to get her these headphones at a very cheap price and he came to the airport and put them in the bag,” Mr Herran told FIVEaa radio on Thursday.

Host David Penberthy, translating an earlier interview with the lawyer, said: “I also believe her version of the events … however it is here that we have a very grave problem … at this point, we do not have any proof that she really was tricked or that this other person that she refers to exists or is guilty.”

Psychological visits

Ms Sainsbury is, meanwhile, reportedly receiving psychological treatment in her Colombian jail.

Mr Herran, told Channel Nine there are serious concerns for Ms Sainsbury’s state of mind and a psychologist is visiting her at Bogota’s notorious El Buen Pastor prison.

The lawyer also said his client was distraught and speaks a lot about her family in South Australia.

Ms Sainsbury’s fiance Scott Broadbridge is due to speak to the media about her detention on Friday.

Lawyer Stephen Kenny says he has been instructed by Ms Sainsbury to provide assistance to her through her Mr Broadbridge, and the pair will speak together in Adelaide.