A woman who stole about $1 million from the Canterbury District Health Board can now be named.

Antoanette Du Preez pleaded guilty to one charge of representative fraud in August 2019 and was sentenced to three years in prison.

The Serious Fraud Office found multiple fraudulent transactions between January 2013 and August 2018 amounting to $1,062,973.

Despite initially claiming the money was used to fund a gambling addiction, it emerged in court only about one-quarter of the money was actually used for gambling.

Stolen money was also used to fund cosmetic surgery in Thailand, gifts to the woman's family, and a jet ski. High-interest loans were also paid off.

The court heard that many of the people who unwittingly gave her money were from overseas, or spoke limited English.

The 50-year-old ex-admin worker has since left the Canterbury DHB after being caught fiddling the system in 2019.

The CDHB's acting chief executive, Dr Andrew Brant, said after sentencing he was "extremely disappointed" that a former staff member had been charged with false accounting.

"When employed by the DHB, the staff member was responsible for liaising with individuals and at times their insurance companies to arrange payment for healthcare services provided to people in Canterbury who are not eligible to receive publicly funded healthcare."

When concerns were first raised, he said, the DHB's internal audit team found indications of fraudulent activity.

Preez was suspended, police notified, and a third party began an investigation.

It was recommended the DHB improved its internal controls for managing revenue from patients who were not eligible for healthcare services in New Zealand.

"A number of changes" were made, said Brant.

"We have ensured that no patients are out of pocket as a result of the individual's actions, and we are working with our insurers regarding the loss incurred by the DHB."