Home Office to announce review of arrangements with US and EU after rows over McKinnon and Ubani cases

The Home Office is to announce a review of extradition arrangements, including those with the US and EU countries following high-profile rows over the way they are operating.

The main impetus has been the row with Washington over the Gary McKinnon affair, in which the 43-year-old has been accused of hacking into US computer systems.

But the review will also look at the operation of the European Arrest Warrant (EAW). Serious questions have been raised about its working after a dispute between British and German police and prosecutors over a criminal investigation into the accidental killing of a 70-year-old patient in the UK by the Nigerian-born German doctor Daniel Ubani.

The Home Office announcement is expected "imminently" and will place Labour's 2003 Extradition Act under the microscope after just seven years.

David Cameron raised McKinnon's case with Barack Obama in July and said the government, in discussions with the US ambassador here, had raised the possibility of "some of the (sentence), if there is a prison sentence, being served in a British prison".

At the time, the prime minister recognised that McKinnon, who faces extradition and up to 60 years in jail, was accused of a "very important and significant crime" but hoped to find a solution. He was more critical when in opposition, saying there was a clear argument to be made that McKinnon should answer questions in a British court.

Critics have argued that the extradition arrangement with the US means British citizens are not given the same legal protection as Americans. If the US wants to extradite a Briton then it need only outline the alleged offence, the punishment oulined by law, and give an accurate description of the suspect. But British authorities have to prove an individual under suspicion has probably committed a crime.

In the Ubani case, the Home Office said the German authorities acted legally in the way they refused to extradite Ubani, who was being investigated by British police and the Crown Prosecution Service (CPS) for a possible manslaughter charge.

It said: "Dr Ubani was convicted in Germany so the EAW was refused on the basis of the double jeopardy safeguard. This provides a mandatory ground for the refusal of the EAW where the person has been finally judged in a member state for the same acts."

A Home Office spokesman said: "The government has committed to reviewing its extradition arrangements, including the operation of the EAW. We will not pre-empt the findings of the review."

Investigations last year by the Guardian and the sons of David Gray, the Cambridgeshire man given a 10-fold overdose of a painkiller by Ubani in February 2008, uncovered serious questions about the case.

One son, Stuart Gray, a GP, said the EAW appeared "to give all German nationals diplomatic immunity from prosecution in the UK".

The CPS then told the Guardian that "at no stage" during a 14-month British inquiry into the incident did German authorities indicate they intended to investigate or prosecute.

But prosecutors in Germany said: "We never communicated with prosecutors in the UK that we were taking action over Ubani as we were not required to do so; neither is this normal practice. The case was dealt with in writing – Ubani never had to appear before a court – because he had signalled his willingness to accept the court's verdict in advance. In other words, Ubani came to us, not us to him."

When British officials finally suspected Ubani was being prosecuted in his own country, "all informal attempts to obtain information quickly" failed, the CPS said. It did not formally learn of his prosecution and conviction for negligent killing until May last year, weeks after the event and after the Guardian published a story about Gray's death the year before. Ubani was given a suspended prison sentence for negligent killing.

Another of Gray's sons, Rory, who works in Germany as a satellite engineer, said today: "During the last two and a half years we have been subjected to all manner of hypocrisy and deceit from all sorts of people and organisations. But these statements from the Home Office are truly stomach churning."

In February this year, a coroner ruled that Gray had been killed unlawfully. But Ubani, though now barred from working as doctor in the UK is still practising in Germany. Only last week, a regional doctors' chamber in Germany was allowed to investigate his fitness to practise there.