THE sons of a Fenland man who was killed by a German out of hours doctor were arrested after confronting him while he spoke at a conference.

Stuart and Rory Gray interrupted a speech by Dr Daniel Ubani about cosmetic surgery, which took place just 24 hours after the locum was struck off the British medical register for killing their dad David at his home in Manea.

Sixty seconds into Dr Ubani’s speech Stuart Gray - himself a GP - stood up and said: “Why are you speaking here as if you were a competent doctor? Because you are not, Dr Ubani. You were struck off the register of the General Medical Council in Britain only on Friday.

“You have had previous malpractice suits against you. Do you have to be a competent doctor to carry out these procedures, because you are not.

“I am a doctor and I am competent. My name is Dr Stuart Gray. Does that name mean anything to you at all Dr Ubani? It was my father that you killed. What have you to say?”

As Rory Gray starting handing out leaflets, Dr Ubani said in English: “I don’t think this is necessary. We did not come here for this. This case was handled in Germany.”

Rory Gray said: “You killed our father and you avoided British justice. How can you stand up there and pretend to be a doctor when you killed a man through this colossal blunder?”

Dr Ubani was escorted from the podium after he was confronted. The Daily Mail reports that, as Dr Ubani walked off, he said: “Can you show me a doctor who has never made a mistake?” The brothers were then arrested outside.

Dr Ubani was on his first shift in the UK when he injected Mr Gray with 10 times the recommended dose of painkiller diamorphine.

He was convicted in Germany of death by negligence, meaning he cannot be prosecuted in the UK.

On Friday he was struck off by the British Medical Council, which said it had “grave concerns about Dr Ubani’s clinical competence”.