A nun who smuggled more than a 1kg of cocaine into Australia using her high heels has been caught.

Denise Marie Woodrum, 51, was caught at Sydney Airport last August after customs discovered she stuffed cocaine into the heels of her shoes, the Sydney Morning Heraldreported.

But the rogue nun, from the US, has shifted the blame for her illegal activity, accusing a mystery man she met online of grooming and duping her.

After a failed marriage and crippling bills, Woodrum, who lives alone, thought she and her online lover Hendrik Cornelius would one day settle down together.

"Can you promise you will never leave me?" the 51-year-old texted him on July 11 last year, according to the SMH.

"You are my Only and First True Family!!! [sic]"

But a month later she would be caught smuggling cocaine into Sydney.

In court last week, Woodrum's lawyer said the items were meant for Cornelius, but that Woodrum thought she was bringing in artifacts, not drugs.

"She was groomed to provide a financial gain for this person, Hendrik Cornelius, whatever person or persons it was behind this identity," Neil said, according to the paper.

"She went on this trip thinking she was bringing artifacts for him."

Despite exchanging hundreds of texts, Woodrum had never met Cornelius face-to-face.

Woodrum pleaded guilty in January to importing a commercial quantity of a border controlled drug.

But Judge Penelope Wass questioned Woodrum's claims she didn't know she was smuggling cocaine, saying the US nun's story is "inconsistent and unbelievable".

Woodrum had flown from Missouri to Texas and then to Trinidad and Tobago on July 18 before the next day flying to Suriname in South America.

On July 25 she texted someone named Stacie, saying "This whole trip is paid for and will get additional payment for work."

On July 30 she made contact with Cornelius then on August 2 she texted him a list of expenses for hotels and flights before departing to Sydney.

After landing in Sydney, the nun was stopped and questioned by authorities where she told them she'd come to Sydney to see the Harbour Bridge and that the shoes in her suitcase were a gift from her mother.

When the shoes were X-rayed, Woodrum asked, "How much did they find in the shoes? Sorry, just talking to myself."

But after the tests came back positive, she reportedly told authorities: "Why, how much did you find?"

Woodrum will be sentenced next month.