A patient suffered harm after dishonest, inaccurate references enabled wholly unqualified people, including a cleaner, to obtain employment as biomedical scientists matching blood, the High Court has heard.
A judge ruled Francis Ajeneye, a senior biomedical scientist at Homerton University Hospital, Hackney, east London, had received an "unduly lenient" sanction for providing the references and a "proper sanction" must now be considered.
"The damage caused to the public interest is evident in the harm caused to one patient and the manifest risk to which others were exposed," said Mrs Justice McGowan, sitting in London.
The judge said Grace Oni had been employed during 2012 and 2013 as a cleaner at University Hospitals Bristol NHS Foundation Trust, and Titlayo Oyedele had not even met Mr Ajeneye until after the period covered by his reference.
"Unsurprisingly the lack of competence shown on the part of both caused serious concerns about their continued employment and an investigation into the nature of their applications and references began."
In one case, Ms Oyedele had cross-matched and given incompatible blood to a patient which had directly caused harm to Patient A, though it was not permanent, said the judge.
A panel of the Health and Care Professions Council's (HCPC) conduct and competence committee decided in September 2015 that Mr Ajeneye's fitness to practise was impaired because of the lack of integrity he presented to patients - but a caution for five years was a sufficient sanction.
The panel heard Mr Ajeneye had provided a reference for Ms Oyedele stating that she had worked with him for a period of three months as a biomedical scientist at Homerton University Hospital, when this was not the case.
Mr Ajeneye had also provided a similar inaccurate reference for Ms Oni.
The panel said all involved in the case were Nigerian nationals who stated they were trained as biomedical scientists in Nigeria but were registered in the UK with the HCPC.
The panel decided Mr Ajeneye should receive a caution for the maximum period of five years, given his previously "unblemished" record in a career that he "clearly relished".
The panel said it was prepared to accept that Mr Ajeneye totally regretted his misconduct and would never again provide inaccurate references.
The Professional Standards Authority appealed against the sanction on the grounds that it was unduly lenient.
Mrs Justice McGowan allowed the appeal on Friday and ordered a fresh hearing to determine a "proper sanction".
The judge said Mr Ajeneye was an experienced blood scientist who knew the skill required in his post, but had provided two dishonest references to unqualified people "with all the attendant risk to the public that would inevitably follow".
When challenged he said an employment agency had completed the references and he had signed them without fully understanding their purpose.
The judge said she had no doubt that the sanction imposed on him was unduly lenient given there had been two acts of dishonesty and an attempt to place blame elsewhere.
She ruled that the "damage to public confidence caused by the fact that two wholly incompetent and dishonest individuals were employed as health professionals with the assistance and connivance of (Ajeneye) is obvious.
"I do not find that (Ajeneye's) testimonials, his career history, his remorse and his undoubted wish to continue in his post together combine to justify the leniency of the sanction."