The family of a pensioner who died after he was administered a fatal pain relief overdose by an overseas locum doctor have accepted £40,000 in compensation, their lawyers have revealed.

Daniel Ubani injected 70-year-old David Gray with 100mg of diamorphine - 10 times the recommended daily dose.

The German doctor was on his first shift for a GP out of hours service provider in February 2008 when he treated Mr Gray for renal colic at his home in Manea, Cambridgeshire.

A spokeswoman for Anthony Collins Solicitors said negotiations over legal costs continue but the family have accepted the compensation figure from sources which remain confidential as part of the payout agreement.

Mr Gray’s son Stuart Gray, who is also a GP, said: “My father was killed and £40,000 does seem a small sum for the loss of a life, especially when compared to countries like the US. It’s disappointing the value that is put on a life.

“However, we’ve never been interested in the money. The major issue for us is pressing for a change to regulations in this country to prevent a repeat of the situation that led to my father’s death.”

Mr Gray’s family have also lodged a complaint with the European Court of Human Rights against the German and UK governments over the handling of the criminal inquiry into the death, the spokeswoman said.

Cambridgeshire Police, who were investigating Mr Gray’s death, issued a European arrest warrant for Ubani to bring him back to the UK to face a possible manslaughter charge.

But, as the warrant was issued, it emerged that legal proceedings had already been instigated in Germany.