The long nightmare of a legal battle all started for the man, named as Sergii I, in 2008 when he appeared on an Interpol red alert list for a double murder dating back to 1997.

He was listed as one of two suspects in the double homicide of two Germans in a residential area in the province of Valencia, reports newspaper El Pais.

At first the Russian citizen and US resident was detained for two months in the US where he legally lived before being extradited to Spain in August of 2008.

There he spent two years in prison and two more years on conditional release, without being able to leave Valencia.

In 2012, the presiding judge decided to dissolve the jury and acquit him after finding that there was “absolutely no evidence against him”.

All the alleged evidence of the double murder had been destroyed years before after the other suspect, a Russian citizen named Vasile P., had been acquitted.

During the trial for Vasile P., who had been extradited from Switzerland, the court had also said that there was no evidence against either suspect. But the search and arrest order for both men remained in place.

The Interpol alert surfaced when the Russian-American man applied to join NATO forces. He said that he did not oppose the extradition order then because he was promised that it would be “a quick trial”.

“During the two years that I was in prison, I was not treated like a precautionary prisoner: I was in with people from [Basque militant group] Eta and I feared for my life in prison,” he said through his lawyer.

In his complaint seeking €10 million, the man argues that the Spanish justice system infringed upon his fundamental rights, that he was innocent and the whole debacle was due to judicial error.