A mug on Tanya Nasir’s desk bore the slogan: “The world’s best nurse.”

It was a big claim, but the 45-year-old was no stranger to making such claims about her experience, qualifications and life.

Cardiff Crown Court heard her deny nine counts of fraud by false representation but she has now been convicted.

The mum-of-two, of Rickmansworth, Hertfordshire, arrived at Bridgend’s Princess of Wales Hospital as a ward manager in September 2019.

It was a senior position in the neonatal unit caring for ill and premature babies. Four months later she was suspended, and two days before a November 2020 disciplinary hearing she resigned.

In January 2020, a paediatric matron noticed a problem with her Nursing and Midwifery Council number.

In her job application she said she gained her nursing diploma in 2010, but the code began “13”. That signified she qualified in the financial year 2013-14.

The matron, Sian Townsend, went through her CV and application to see if there were other lies. There were.

Nasir claimed to be a specialist neonatal nurse who spent five years at Chelsea and Westminster Hospital in London.

She claimed to have been a combat medic, to have worked across the globe doing military and humanitarian work, and to have worked with Oxfam and the Red Cross.

Her children’s school and surgery believed she was a doctor, while others were told she was a captain and a major.

Friends believed she was vital to the Army’s Covid response in Wales. Colleagues were told she knew child murderer Myra Hindley.

While Nasir was studying for her adult nursing diploma at Buckingham New University in 2010 she appeared in court to admit four counts of benefit fraud.

A staff member spotted a hearing report, so she was summoned to a disciplinary hearing and asked why her conviction was not disclosed.

She provided a fake probation letter which said she did not have to tell the university.

It accepted the explanation and she continued the course.

When she applied for the job in Bridgend, Nasir had an expansive – and false – CV.

She claimed experience in intensive care, A&E medicine and children’s palliative care. She made up qualifications, multiple degrees, said she had led platoons of 250 and had extracted VIPs from war zones.

When her Brecon home was searched following her April 2021 arrest, bundles of fake certificates were found.

However, she had worked in the neonatal unit of Hillingdon Hospital in London. That hospital said it had reviewed all matters related to the case, and that it “maintains rigorous protocols for employment and patient care, which we continuously evaluate and improve”.

Investigators later told Nasir they had proof from HMRC she had not worked at Chelsea and Westminster Hospital.

She said there were no tax records because she had volunteered – for five years.

In court she insisted: “It’s my life as I have lived it… all the information in my application forms is correct.”

In Nasir’s Princess of Wales Hospital application she detailed referees who could be contacted by email.

One was a “senior nurse” Nasir claimed to have worked with at Hillingdon Hospital called Maureen Westphal. The other was an Army cadet force officer, Maj Matthew Nash-Yearwood.

Interviewed by fraud investigators, they said they did not know they had been named as referees and had not provided references.

The Princess of Wales Hospital did have a reference from Ms Westphal’s Hillingdon Hospital email account.

But it was written after she had left Hillingdon – the account had not been shut down, so Nasir took it over.

Meanwhile, a reference apparently from the Maj Nash-Yearwood was from Nasir’s own email.

Hertfordshire born and bred, Nasir had lived with her mother and stepfather.

She told the court she had fled an abusive relationship with her son and daughter and lived in a refuge before deciding to become a nurse and moving to Wales in the summer of 2019.

When presented with evidence she had not been in the Army, she refused to accept it. But when asked to recall her eight-digit Army service number, she could not.

She sent photos to friends of herself wearing uniform. One she claimed was taken in Kenya, despite it showing a British-looking garage block.

Quizzed about how she travelled to Afghanistan, she made no mention of flying from an RAF base, but claimed she might have flown from Heathrow or Gatwick.

In the witness box she appeared shocked that anyone would challenge her version of events.

Her barrister told the jury that no-one had ever complained about her work and said that no child suffered at her hands.

Those who worked with Nasir said she had a confident air.

When the interview panel at the Princess of Wales Hospital gave her the neonatal ward manager job in 2019, they thought they had appointed a qualified, experienced nurse.

They had appointed a fantasist and a liar.

Throughout her trial, former Hillingdon and Bridgend colleagues sat quietly in the tiny public gallery of court nine.

Sometimes they cried as they heard evidence.

“We thought she was one of us,” one said. “But she wasn’t.”

Nasir has been given bail and will be sentenced on 24 September.