Jan Olszewski, who came to the UK during the Second World War, settled in Hadassah Street, Siddal, with his wife. He worked in textiles and engineering and she was a nurse.

Mr Olszewski died in 1998, five days after his wife Kasia, leaving an estate of £53,000.

The couple had a double funeral and were buried together at Stoney Royd, Halifax.

They had no children but Mr Olszewski was much loved by the family he married into.

Around three years after his death those relatives were shocked to learn of his Polish family.

International Fraser & Fraser, a firm of international probate research-ers, discovered he had six siblings his hometown of Jedrzejow, about 100km north of Krakow.

They discovered Mr Olszewski had joined the Tatra Highland Unit at the beginning of the war and been sent to fight in Russia, before joining the Polish Free Army in the UKlater on. It is not known why Mr Olszewski never re-established contact with his family – but his estate was divided between 46 heirs in Poland.

His niece, Sophia Fris, of Southowram, said Mr Olszewski never mentioned family in Poland.

"They got the money in Poland but we had him for all those years. He was a lovely man."

Mr Olszewski's story will be on Heir Hunters on BBC1 at 9.15am.