More than 220 medics may have treated patients after being told they had passed a crucial exam they had actually failed.
The mistake by the Federation of the Royal Colleges of Physicians of the UK was blamed on an administration error.
It also resulted in 61 doctors being told they had failed the exam when they had passed.
The British Medical Association (BMA) yesterday called for an urgent investigation and said the error has ‘far reaching’ ramifications for doctors and patients.
Those impacted by the error are being informed by the federation, and exam fees will be refunded and resits will take place free of charge.
Professor Philip Banfield, chair of the BMA council, said: ‘Failing an exam is devastating and has consequences for doctors as they work their way up the ladder of expertise; being told you have failed when in fact you have passed, is even worse.
‘For those 222 doctors who have spent the past 18 months believing they had passed, but have not, they will be equally devastated and unsure what lies ahead.
‘The moral, legal and governance aspects of this truly terrible mistake are far-reaching and must not be under-estimated by the public, Government, and the NHS.’
The British Medical Association (BMA) have called for an urgent investigation after more than 280 medics were allowed to treat patients despite having failed the relevant exam

The mistake was caused by an administration error, according to the Federation of the Royal Colleges of Physicians of the UK
Some 1,451 medics took the MRCP(UK) Part 2 Written Examination in September 2023, according to the BMA.
The test is one of three parts which must be taken by doctors who wish to progress in their training in a medical specialism.
The Federation said incorrect results were given because of a data processing issue.
The total included 222 doctors who were told they had passed when they had failed, and 61 who were told they had failed when they had passed.
Prof Banfield added: ‘The ramifications of this appalling situation are far-reaching for doctors and patients,’
‘All doctors should have confidence in an exam result – they are central to their careers and to the skills they bring to medicine.
1,451 medics took the exam in September 2023; 222 doctors were told they had passed when they had failed and 61 were told they had failed when they had passed
‘There must be an immediate independent investigation into this, including how routine audit processes have taken so long to identify this error.
‘The federation must commit to significant support and compensation for all the doctors whose lives and careers will be in turmoil today because of this mistake.
‘We want all doctors affected by this catastrophic error to contact the BMA. We are talking to the Royal College of Physicians, and we are exploring options for support, compensation, and recompense with our legal team.’
Dr Mike Jones, executive medical director of the Federation, said the organisation ‘deeply and unreservedly apologise for this situation’.
He added: ‘We appreciate how distressing the candidates affected will find this, and for some it will create an additional burden to the hard and vital work they do.’