Lopez is a descendant of a Jewish family that was forced to convert to Catholicism during the Inquisition. Like many other descendants of Marranos (Bnei Anusim in Hebrew), he was never told that he was a Jew. But Lopez, whose job is to identify counterfeit euro bills in Spain's National Central Bank, followed the clues his mother and grandmother had left over the years and realized, six years ago, that his ancestors had secretly maintained elements of what had been their Jewish life.

"There was a hidden room with no windows in my grandmother's house where she lit candles on Friday evenings after making sure the house seemed empty," Lopez told The Jerusalem Post earlier this month, when we met up here at the fifth convention for Spanish and Portuguese Marranos of the Shavei Israel organization.

"It was hard to maintain Jewish customs. I was raised in a small and highly religious village near Toledo. My grandfather, who fought in Spain's Civil War, was accused of being a Jew and was killed over it after the war," he went on. "After that, my family withdrew further and kept the secret even tighter."

Lopez wore a kippa to the convention. Underneath his shirt he was wearing tzitzit, just as his grandfather did.

But he does not normally cover his head and is still hesitant about discussing his new/old Jewish identity. Even though he came out of the closet for the convention, Lopez's own family is not aware of its Jewish heritage.

He said he had investigated his relationship to Judaism on the Internet, via the Spanish archives of the Inquisition that meticulously document its actions, and through friends and relatives.

"There are probably around 20,000 Marranos in Toledo who continue to maintain a Catholic lifestyle," he said. "Ancient customs like not mixing meat and milk or not eating pork have been customary there for ages and, according to the books, these point to the strong presence of the Jewish community in Toledo prior to the Inquisition."

Lopez is one of a growing number of descendants of Jews hunted during the Inquisition to have emerged from the shadows in the past two decades, looking to reconnect with the Jewish people and return to the faith.

Spanish Jewry was one of the oldest and most successful Diaspora communities before the Inquisition. But from 1391, it faced waves of expulsion, persecution and forced conversions. Finally in 1492, the Spanish monarchs, Ferdinand and Isabella, formally expelled the last Jews. Many of those who remained behind had been compelled to convert to Catholicism, but preserved their Jewish identity covertly.

Tens of thousands of Spanish Jews sought sanctuary in Portugal. Then, in 1497, the Portuguese king presented the Jews living in his realm with a choice: convert or die. Some chose death, but most either fled or were dragged to the baptismal font.

When the doors of the New World swung open in the 16th and 17th centuries, Brazil came to play an important role for the Marranos; it offered the possibility of a new life and the hope of one day returning to the faith of their ancestors. But the long arm of the Inquisition reached across the Atlantic and continued to hunt down those accused of secretly practicing Judaism.

The derogatory name Marrano, "pig's leg" in Spanish, was given to the converted Jews by their Christian neighbors. "If someone was suspected of keeping his Judaism secretly, the members of the community would give him a piece of pork to eat in front of them. If he or she refused, they would be brought in front of the Inquisition's court for a cruel trial," Rabbi Eliahu Birnbaum explained.

Birnbaum, 49, made aliya from Uruguay 36 years ago. He works for the Chief Rabbinate and volunteers with Shavei Israel among the Spanish-speaking communities of the Bnei Anusim. During the convention, he gave advice to participants, prayed with them, explained the origins of traditions and, at their request, taught them how Shabbat should be observed.

While the Spanish still do not like to be called Marranos, the Portuguese feel differently. "In Portugal, Marrano means not just a pig's leg but is also an adjective used to describe a determined person who fights for what he believes in and doesn't give up," Prof. Filipe Ferráo, 51, a neurophysiologist from the University of Porto, the second largest city in Portugal, told the Post.

"I was raised in Porto with all these customs I didn't understand. For example, we were constantly told not to count stars while pointing to the skies. We were told that if we did so our fingers would be calloused. Years later, I learned that Jews know Shabbat is over only when they count three stars in the skies. Our parents were afraid that if we did so, we would be suspected as hidden Jews," Ferráo recalled.

"Our dining table was rectangle and whenever I placed bread on it horizontally, my mother used to come over and tell me to move it. She never said why, but it became second nature to me. When I grew up, I understood it was in her attempt to prevent me creating a cross."

It took Ferráo 20 years to complete the process of returning to Judaism. He and 15 other Marranos were converted by a Jerusalem rabbinic court in January 2007. He came to the convention to support and inspire those who are trying to follow suit.

"One needs to live in a Jewish community with an authorized rabbi for a year before starting the legal process with the rabbinate in Jerusalem, and for me it was impossible since there was no rabbi and no solid community in Porto when I started the process," he said. "But now I feel like I paved the way for others. And I've stayed in Porto to help them."

Ferráo converted with his wife and their younger child, who is 19. Their older child is 26 and married, and was not interested in going through the process.