Jailed Australian drug smuggler Cassandra Sainsbury will reportedly wed her fiancé in a "lavish" Colombian prison ceremony.

Sainsbury has been granted permission to wed Scott Broadbridge behind the walls of El Pastor prison, where she is currently serving a six-year sentence for attempting to smuggle 5.8 kilograms of cocaine out of a Bogota airport, the Adelaide Advertiser reports.

Scott Broadbridge has maintained he would stand by Sainsbury "no matter what it takes". (AAP) (AAP)

The couple's celebrity agent, Max Markson, told the newspaper he was "confident" of negotiating a television or magazine deal to cover the wedding soon after Christmas.

While exact details of the wedding have not been disclosed, a small guest list of family members, wardens and fellow inmates are expected to attend.

Sainsbury had been facing up to 30 years inside the Bogota prison after her arrest on April 12.

Sainsbury was arrested in April with 5.8kgs of cocaine.

But a plea deal was struck that reduced her sentence to six years, and the 22-year-old could be out even sooner with good behaviour.