The court in Kempton, Germany, rejected the application by Dr Ubani for an injunction, which aimed to impose a ban on Dr Gray and his brother Rory Gray from talking to the press across Europe, including the UK.

The court ruled that the brothers can continue to brand Dr Ubani a 'charlatan’ and a ‘killer' but said the sons are not permitted to use 'animal’.

Dr Gray said this is a 'major milestone' for his family and that he will now concentrate on getting Dr Ubani struck off the medical register across Europe.  

He said: 'It’s a major step forward for us. If it was passed then we would not even be allowed to speak to the British press.

‘There is going to be a fitness-to-practise hearing through the local government, and my brother and I are pressing hard to get him struck off Europe-wide.’

Dr Gray's father David died after Dr Ubani gave him an overdose of diamorphine on his first UK out-of-hours shift. Dr Gray and his brother Rory have sought to raise the profile of the case by speaking out both in the UK and Germany.