A man whose Polish parents harboured Jews during the war and provided support to the Jewish Underground ahead of the Warsaw Ghetto Uprising has said he is "delighted" to see them finally recognised as Righteous Among the Nations.

Andrzej Pluskowski, 72, has spent more than 30 years piecing together both his parents' history and his own beginnings, having been born in a cellar during a German bombardment in Warsaw, in the middle of the Jewish uprising that saw 13,000 killed.

His father, Józef Pluskowski, had been a school inspector and an active socialist who, when the Germans invaded in the late 1930s, worked for the Polish underground, acting as their liaison to the ghetto.

Mr Pluskowski knew little more of his father's activities; he died shortly after they fled the country following the Second World War, and his mother Irena - with whom he settled in the UK at the age of nine - seldom spoke of their past.

It was while reading a Polish book on the ghetto that Mr Pluskowski found a passing reference to his father. Further investigation proved fruitless until a few years ago, when he was invited to Poland, as one of its youngest survivors, for commemorations of the uprising.

There, Mr Pluskowski visited the Jewish Historical Institute in Warsaw, where the chief archivist remembered his surname. She found testimonial letters written by a Jewish family who his parents had hidden in their apartment for two-and-a-half years. Records stated they had also provided refuge for another seven Jewish families.

As more details emerged, Mr Pluskowski learned, for example, that his mother had been trained to walk with weights under her coat in order to bring supplies and arms to the ghetto - she is recorded as having delivered 90 hand grenades prior to the uprising.

After the destruction of the ghetto in 1944, Jósef was awarded Poland's highest military decoration and, three days later, sent to a prisoner of war camp in Germany. After the war, he returned to Poland where he was imprisoned by the authorities for having supported the Polish government in exile.

But, as his son has now learned, he and his family were saved by the intervention of international Jewish organisations, who wished to repay the favour for saving so many lives and secured Jósef's release and smuggled him out of the country in early 1948.

About six months later, Andrzej and his mother were given false Jewish identities by the Jewish Underground working to get Jews out of Poland. They left the country with a group making aliyah but, instead of heading for Israel, they were reunited with Józef and settled in Paris. Following Józef's death in 1950, Andrzej and his mother came to the UK .

"It was reciprocal help in every way," Mr Pluskowski said. "My parents helped the Jews, and they supported us right up until I was 18. Once we came to the UK, the Jewish Labour Committee in New York paid for my education.

"I only know because my mother, who never learnt English, asked me to write thank-you letters on her behalf."

The ceremony honouring Jósef and the now 96-year-old Irena Pluskowski will be held at the Israel Embassy in London next Wednesday. They will join the list of non-Jews around the world who are recognised by Yad Vashem as having risked their lives or liberty to help Jews during the Holocaust.