The backgrounds of 3,000 foreign doctors are being urgently checked after a conwoman with no qualifications was allowed to work as an NHS psychiatrist for 22 years.

Zholia Alemi, 56, claimed to have a degree from the University of Auckland in New Zealand when she came to work in the UK in 1992.

In reality, the convicted fraudster had flunked her first year and dropped out.

But nobody at the General Medical Council, the watchdog responsible for vetting the background of medics, checked whether her documentation was genuine.

At that time, doctors from certain Commonwealth countries could be cleared to start work simply by presenting their qualifications, without sitting any assessments.

Zholia Alemi, 56, worked as an NHS psychiatrist for 22 years when she came to work in the UK in 1992 despite not having any qualifications. No one at the General Medical Council, the watchdog responsible for vetting the background of medics, checked whether her documentation was genuine

It meant that for more than two decades from 1995, Alemi was free to treat thousands of mental health patients in the NHS, apparently prescribing medicine, making assessments and even sectioning some of the most vulnerable in society.

The deception by Alemi, thought to be of Iranian extraction, was only discovered after she was convicted of trying to fake the will of an elderly woman to steal her £1.3 million fortune.

A judge described her as 'despicable' and jailed her for five years last month.

The Daily Mail learned about the GMC's review after being alerted by an investigation into Alemi's background by Carlisle's News and Star newspaper.

The fraudster, who could have earned up to £100,000 a year working as an NHS psychiatrist, enjoyed the trappings of wealth – buying bottles of expensive champagne as investments and driving a red Lotus Elise sports car.

It is understood that when she came here, Alemi showed officials a Bachelor of Medicine and Bachelor of Surgery certificate.

In reality, her only qualification was a degree in human biology.

Last night patients' groups called for a public inquiry as police confirmed their investigation into Alemi was ongoing.

John Woodcock, independent MP for Barrow and Furness, in the Lake District, where Alemi was most recently working, said the case was 'hugely alarming'.

Alemi, who could have earned up to £100,000 a year working as an NHS psychiatrist, had also been investigated in 2012 after failing to disclose a conviction for careless driving

'If this had been one individual that had slipped through the net it would have been concerning, but the idea that it could be a systemic loophole that has been exploited is hugely alarming,' he said.

'It is understandable that patients are calling for an inquiry – this is of sufficient magnitude that that may well be necessary.'

The GMC admitted its checks had been inadequate and confirmed an 'urgent investigation' was looking into the backgrounds of 3,000 doctors who came to work from Commonwealth countries, before 2003, in the same way.

Incredibly, Alemi had been investigated and given an official warning by the Medical Practitioners Tribunal Service in 2012 after failing to disclose a conviction for careless driving.

She also sectioned psychiatric patients for treatment without the authority to do so, and was banned from working for 12 months as a consequence.

Despite this, no one thought to examine her background or the reliability of her qualifications.

One woman, who claimed one of her relatives had been poorly treated by the fake psychiatrist, wrote on Facebook: 'The way she (Alemi) treated my relative was appalling and now that I find she was not a qualified psychiatrist, and was allowed to treat patients for 22 years, I am beyond livid.'

Joyce Robins, of Patient Concern, said it seemed 'incredible' that someone could slip through the net in such a fashion.

She added: 'There definitely needs to be a public inquiry – how many patients will she have come into contact with? Patients will be horrified that the proper checks weren't in place.'

GMC chief executive Charlie Massey said the doctors being checked represented just 1 per cent of the 300,000 medics on the register and that vetting was much more rigorous today than it was in the 1990s.

But he admitted: 'It is extremely concerning that a person used a fraudulent qualification to join the register.'

Last night, the GMC could not say exactly where Alemi had worked during her career, although she is understood to have had links to West Yorkshire, Lancashire and Scotland.

She was working as a locum old-age psychiatrist at Cumbria Partnership NHS Foundation Trust in 2016 when she met 84-year-old Gillian Belham.

Alemi befriended Mrs Belham, but when she was accused of stealing watches from the pensioner, police discovered she had been working to take control of her finances – even deceiving some of her friends into being signatories on a new will.

The Cumbria trust said it had launched a review.

The Department of Health said: 'We expect the GMC to investigate how this criminal was able to register as a doctor and put measures in place to make sure it can't happen again.'