Daniel Ubani, who had been recruited by an agency to provide out-of-hours cover in Cambridgeshire, arrived in the UK the day before the Februrary 2008 incident. During a visit to 70-year-old David Gray, who suffered from kidney stones and renal cholic, Ubani administered a 100 mg dose of diamorphine that killed Mr Gray within hours.
The doctor claimed later that he had been “too tired” to concentrate, which led him to use the wrong drug.
"This is a deeply disturbing case and one that must be thoroughly looked into. We have to ensure any lessons are learned," Christine Braithwaite, head of investigations and enforcement for the National Health Service's care quality commission, told the Guardian.
The case has also generated friction over Germany's response to an extradition request by British authorities. Though he has been suspended from working in the UK by the General Medical Council there, Ubani continues to work from his own practice in Witten, North Rhine-Westphalia. In April, the German courts gave Ubani a nine-month suspended prison sentence and fined him €5,000 for the accidental death.
But this was not enough punishment for British officials hoping to bring him to trial in the UK.
"It is disappointing that this doctor, although now convicted of an offence, was not held to account in this country," the British Department of Health told the paper.
Scores of German doctors travel regularly to Britain for lucrative short-term stints to help out their overstretched NHS colleagues. They can often make as much in a few days in what they make in Germany in an entire month.