The woman who worked for 23 years in the UK under a false University of Auckland qualification was exposed in three simple phone calls to New Zealand.
Zholia Alemi was jailed for fraud in October after she faked an elderly woman's will in an attempt to inherit her £1.3m ($NZ2.4m) estate.
Following the conviction, News and Star newspaper chief reporter Phil Coleman told Nine to Noon he was intrigued to investigate the case further. It was then that he found Alemi's medical degree from University of Auckland, which she used to register in the UK in 1995, was actually fake.
"My plan was to basically start at the beginning of her professional career and see what had been going on for the 23 years during which this lady had been working on in the United Kingdom.
"It took three simple phone calls to New Zealand. One was to University of Auckland, where Alemi claimed to have got her primary medical qualification - a bachelor of medicine and a bachelor of surgery. And two more phone calls to the Medical Council of New Zealand and those three phone calls were enough to confirm this lady's medical qualification was completely fake.
"She never qualified as a doctor, she dropped out of her medical training after just one year, in fact her only qualification was a degree in human biology."
She managed to deceive authorities under an old system which used a more relaxed approach towards a person who was qualified in a Commonwealth country, he said.
"Back in 1995, when Alemi joined the medical register, she somehow managed to acquire a certificate confirming her graduation in 1992 with a degree, which we now know she never had, and she also presented a letter of recommendation, apparently from her former employers, presumably medical employers, in Pakistan."
However, he said he had not seen the recommendation letter documents yet.
Mr Coleman said that Alemi, under deception, had the power to diagnose patients, prescribe powerful medications and even to detain patients against their will in cases where that may be needed.
"Effectively Commonwealth doctors were taken on trust. It seems there was no stringent vetting or secondary checking and that was the mechanism through which Alemi achieved her 23-year career as a bogus psychiatrist."
The General Medical Council (GMC) - the doctors' watchdog - said that system was terminated in 2003 and a more rigorous approach and had since been in place.
The records of up to 3000 doctors in the United Kingdom - who registered for a licence under the same rules as Alemi - are now being urgently reviewed.
Mr Coleman explained how Alemi befriended an elderly 84-year-old woman, the victim in the case, who had recently become a widow.
"[The patient] was struggling in life because she'd recently been bereaved and clearly her carers and the medical professionals around her felt that some sort of psychiatric assessment would be sensible.
"Instead of helping this lady, Zholia Alemi discharged her from the service having given her a clean bill of psychiatric health.
"She took her for meals in hotels, she volunteered to do her shopping and she volunteered - and this is hugely ironic because the 84-year-old lady involved was a former Bank of England worker - she volunteered to help this lady with her finances."
At some point, a collection of watches belonging to the elderly woman's late husband disappeared, which raised the suspicions of a carer, who was regularly visited.
Police then began an investigation which led to raids on Alemi's office and house where financial papers and bank cards belonging to the widower, and the forged will were found, he said.
One of the major clues that showed the will was forged was that Alemi had the habit of misspelling sign as 'sing' and that also showed in her personal correspondence, he said.
After the findings were revealed, one family of a patient she cared for had expressed their discontent, he said.
"I can tell that I've had contact with the family of one patient and the adjective that comes to mind when describing their emotions and their state of mind at this point are angry, feelings of being let down and bewilderment that this could have ever happened."