Convicted Australian drug trafficker Cassie Sainsbury has been released from a Colombian prison less than three years into her six-year sentence, her lawyer has confirmed.

Key points: Cassie Sainsbury was jailed in November 2017 in Colombia for cocaine trafficking

Cassie Sainsbury was jailed in November 2017 in Colombia for cocaine trafficking The Adelaide woman was aged 22 when she was arrested at Bogota's El Dorado airport

The Adelaide woman was aged 22 when she was arrested at Bogota's El Dorado airport She has told Channel Nine that the experience has been "a massive learning curve"

Ms Sainsbury, a former personal trainer from Adelaide, was jailed in November 2017 after being arrested at Bogota's El Dorado international airport in April that year with 18 packages of cocaine stashed in her luggage.

Sainsbury's Colombian lawyer Orlando Herran has confirmed to the ABC his client has been released from prison in Bogota.

In an excerpt of an interview with Channel Nine's 60 Minutes program posted on social media, Sainsbury said she had "grown up" during her time in jail.

"I can say that I grew as a person — I've grown up a lot," she said.

"I learnt a lot about myself, I learnt a lot about people … I've learnt how to analyse people better.

"I've learnt not to trust people so much, it's been definitely a massive learning curve.

"But at the same time, everything I've been through in prison, everything I've learnt, I wouldn't change it — because it's made me a stronger person, it's made me who I am today."

Cassie Sainsbury was sentenced to six years' jail in November 2017. ( AP: Fernando Vergara )

Sainsbury was 22 at the time of her arrest and was stopped while trying to smuggle 5.8 kilograms of cocaine inside 18 separate packages of headphones.

She was initially facing up to 21 years in prison, but had her sentenced reduced to six years after a judge accepted a plea deal.

Coronavirus may have led to early release, lawyer says

Sainsbury spent the sentence inside Colombia's El Buen Pastor prison, which is known for its harsh conditions.

Her former lawyer in Australia, Stephen Kenny, said she may have been released early because of coronavirus concerns in the Colombian prison system.

"Being in prison anywhere in the world at the moment would be very difficult particularly with the virus and the fact that prisons are very much like a cruise ship in the sense that everyone is locked on them," he said.

"If a virus got in there it could be quite deadly.

"About 4,000 prisoners were due for release but it's not clear at this stage whether Cassandra is one of those who is being released in the general humanitarian release or whether she has actually come up for parole and she's been released on parole."

Mr Kenny said if that were the case, Sainsbury would serve her parole in Colombia.

At the time of her imprisonment, her Colombian lawyer said she may end up serving less time — about three years — with good conduct.

Her case drew mass attention in Australia and shone a light on foreign drug mules in Colombia, the world's largest cocaine producer.

At the time, Colombia's National Penitentiary Prison Institute estimated about 880 foreigners were detained in different prisons across the country, with most serving time for narcotics trafficking.

A police officer escorts Cassandra Sainsbury into a court hearing in Bogota in August 2017. ( AP: Fernando Vergara )

In an interview with 60 Minutes in September 2017, Sainsbury said she thought she had accepted a job as a legitimate courier transporting documents for $10,000 plus flights.

"I had outstanding bills, I suppose I took the risk," she said.

But at the last minute, she said the plans were changed and she was sent to Colombia where a "mastermind" known only as Angelo threatened to kill her mother, sister and fiance if she did not transport Angelo's drugs.

Mr Kenny, who represented Sainsbury's ex-fiance Scott Broadbridge, told the ABC in 2017 that "she could have been facing 20 years" in jail.