They have travelled more than 10,000 kilometres in the search for justice, but a long fight still lies ahead and time is running out.

Twenty-eight Spaniards, victims and the close family of victims of the 40-year dictatorship of General Francisco Franco, are in Argentina at the invitation of a local judge.

The judge, Maria Servini de Cabria, has issued international arrest warrants for four former Spanish policemen accused of torture. The move came nearly 40 years after Franco's death and Spain's return to democracy.

The victims say their search for justice in their homeland has come to nothing.

"I think we will find justice in Argentina, because we've not found it here, wherever we've looked," said 88-year-old Acension Mendieta, whose father was killed by the Franco authorities, leaving Madrid's Barajas airport for the long overnight journey to Buenos Aires.

On their arrival several hours later at their hotel in the bohemian San Telmo neighbourhood of Buenos Aires one of the group's spokesmen, Josu Ibargutxi, himself a victim of torture, said there was great anxiety among thousands of Spanish victims.

"These 10,000 kilometres that we've travelled are no barrier, even for those 88-year-olds in the group. This is the only country in the world willing to denounce the barbarity," Ibargutxi said.

Dark memories

Two of the four accused of torture are already dead. The two others are Jesus Mu?ecas Aguilar, and Juan Antonio Gonzalez Pacheco, known as Billy the Kid. His victims said he took particular delight in his work and openly walked the streets of Madrid, defying his victims.

Francisco Franco came to power in Spain in 1936 at the end of a particularly bitter civil war in which countless human atrocities were committed by both sides. Once in power the regime governed with an iron fist. Opponents were imprisoned and tortured and many thousands fled into exile.

Franco died in 1975 and democracy returned to Spain two years later. Despite calls to prosecute those accused of human rights abuses, little was done. Spain wanted to move forward, and put its dark past behind it.

But the seeds to seek justice on an international scale were planted, ironically in Spain, in a case that tested whether those accused of crimes against humanity could be tried anywhere in the world by any country willing to prosecute them.

It was a Spanish judge, Baltasar Garzon, who in 1998 ordered the arrest of the former Chilean dictator, Augusto Pinochet. The general spent more than a year under house arrest in the United Kingdom while the Spanish authorities tried to extradite him to stand trial on human rights abuses committed in Chile in the 1970s and '80s. He was released on grounds of poor health, and was eventually allowed to return home where he died a free man in 2006.

But a precedent had been set. Suddenly former police and military torturers, who had enjoyed immunity from their crimes, often walking the same streets as their victims, were nervously looking over their shoulders.

"Those things that for some might not mean much, for the victims we've got here, tortured victims, knowing that those people might be extradited, is a huge relief," said Maxmo Castex, one of the Argentine lawyers working on the Spanish case.

Argentina's past

Argentina, of course, has suffered its own dark military history. Up to 30,000 people were kidnapped, tortured and killed by the military regime that governed from 1976 to 1983.

The early civilian governments, following Argentina's return to democracy, pardoned or granted amnesty to those accused of carrying out those atrocities.

It was only under the presidency of Nestor Kirchner, who came to power in 2003, that the trials resumed, and some former military leaders and those they ordered to carry out the crimes were tried and imprisoned.

Those fighting similar battles in Spain could only look across the Atlantic in frustration - until now.

While in Argentina, the Spaniards are giving their testimonies to judge Maria Servini de Cabria and also meeting with Argentine victims.

It's a long and slow process, this business of seeking justice.

Many of the Spanish victims, as well as those accused of carrying out the crimes, have died. Most of those still living are old and frail. However, they are determined to do whatever is necessary, to travel to the other side of the world to right the wrong, and put their and their country's nightmares to sleep.