Cassandra Sainsbury's fiancé describes how she was "lured" to Colombia.

The partner of 22-year-old Cassandra Sainsbury, who is currently behind bars in a Colombian prison after being accused of trying to smuggle 5.8kg of cocaine out of the country, has made explosive claims about who is responsible for her misadventure.

In an interview set to air this weekend, Scott Broadbridge told Channel Seven’s Sunday Night program that his fiancée was “lured” to Colombia by other Australians.

Scott told reporter Denham Hitchcock the he was “surprised” to learn that Cassie had flown to Colombia.

He hints that other Australians were responsible for Cassie’s shock trip – which she claims was for “work purposes” – and also said he had seen mystery “payments”.

Cassie Sainsbury and her boyfriend Scott Broadbridge. (Image via Facebook.)

"You saw the payments from them?" Hitchcock asks in the teaser for the episode.

"Yes," Broadbridge says in response.

Since her arrest, Cassandra has maintained that she was "set up" and said she was told the packages in her suitcase contained headphones.

cassie fiance IV sunday night
Scott speaks to Sunday Night about his partner's ordeal. Image via Channel 7.

She was arrested at Bogota International Airport when police found the drugs concealed in her luggage. If convicted, she faces up to 20 years behind bars.

Cassandra will also speak to Sunday Night about the moment she was busted at the airport with the cocaine.

cassie sainsbury plea deal
Source: AFP

Despite being in prison for more than a month, Cassandra has only just been visited by her family and fiancé, on separate visits.

After originally being denied access to visit Cassandra, Scott was able to see the 22-year-old earlier this week.

It's believed the couple - from South Australia - spent just over an hour together at the El Buen Pastor prison before Scott re-emerged.

The full interview with Scott will air on Sunday 8.30 on Channel 7.