One night last week as I was walking through central Lublin with a group of Jews from London, an Orthodox rabbi among us was approached by an excited, middle aged man wearing a black hoodie.

Pawel Matraszek accosted the rabbi, speaking in German and then Yiddish. "I can't believe it, a real Jewish rabbi is here," he said.

What followed was an episode that starkly illustrated the strange poignancy of modern Poland for many Jews.

There is no rabbi in Lublin and only 40 Jews remain of a pre-war population that numbered over 40,000. So Mr Matraszek, a Polish Jew born in Lublin, was thrilled to meet Rabbi Mendel Lew and to find that he was accompanied by three other London rabbis, the president of the United Synagogue, myself and a couple of others.

Though it was nearly midnight and a sharp frost was settling, Mr Matraszek insisted that we see the shtiebel he visits almost daily as caretaker.

He led the somewhat nervous group through the streets to a gate in the wall on Lubartowska Street, which he unlocked. Down a dark, uneven alley was a door leading into Chewra Nosim - the only synagogue in the shadow of the former Jewish ghetto to have survived the Second World War.

Old furniture and tools were piled inside the front door. The staircase was lined with photos depicting post-war life for Jews - families celebrating festivals and children in school line-ups.

Upstairs, was a cramped meeting room with a piano and a scruffy kitchen. Mr Matraszek hurried through, clearing the way for us, tidying as he went, pointing out photos of his mother and talking eagerly through the interpreter accompanying the group.

"It is very exciting to be able to show the synagogue to you," he said. "We are trying to keep this place going for the Jews of Lublin and for future Jews. We meet here and hold Shabbat meals."

He then opened a door off the kitchen and led the way into the small synagogue itself. It was a cleanly painted, unembellished room, containing benches, bookshelves and a bimah, which looked like it was once a wardrobe.

On a table was a Torah scroll rotted through, but still protected under a velvet cloth. In a cabinet was a mezuzah, a menorah, a disintegrating tefillin and a tallit prayer shawl. On the wall was a photo of Meir Shapiro, founder of the famous Chachmei Lublin Yeshiva.

For years after the Second World War a group of Jewish survivors lived here. "It probably escaped destruction because it was on the very edge of the ghetto," said Mr Matraszek.

Later, they would come to meet and pray. According to the local history group, Theatre NN, the building was used as a synagogue until 1984 and a barmitzvah ceremony took place in the early 1990s.

"I came here regularly as a boy with my mother during Soviet times," said Mr Matraszek. "Jews used it as a place to discuss their experiences during the war and under Communism and to meet other Jews."

"I had no idea this was here – we all know about the Lublin Yeshiva, but this is something different, it feels alive and much loved," said Rabbi Mendel Lew, who leads the largest Orthodox community in Europe, at Stanmore and Canons Park Synagogue. "I can feel the uncertainty, fear and despair that was experienced here after the war."

The group , who were on a trip to visit the new Jewish Museum in Warsaw, asked Mr Matraszek to join them in the Maariv evening prayer. It was clear that he was unaccustomed to praying in Hebrew, a legacy of the 40-year Soviet era when religious
practice was discouraged.