Like many people after the 2016 EU referendum, Andrew Evans started thinking of ways he might be able to retain his European passport.

The 37-year-old from Barnet, north west London, decided that his grandfather, who was Jewish, was a good place to start, so he started to investigate.

What started off as “quite a cynical attempt to get a European passport”, soon became something much more — a “great story and discovery of what he must have been through to stay alive”.

Mr Evans’s grandfather, Adolph Lempert, was a mystery during his childhood because he left his wife, Mr Evans’ grandmother, for another woman.

“He was the kind of person with stories and myths and rumours about him,” Mr Evans said.

“He never spoke about his past.”

His research has shown that Mr Lempert was born Adolph Zuckerkandel in 1913, in Lemberg, now Lviv, the largest city in western Ukraine. He survived the Holocaust by lying about his name and pretending he was Dutch.

While the rest of his family was killed, his grandfather made it to London with no passport and even managed to serve in the RAF for the rest of the war.

Upon discovering his grandfather’s story, Mr Evans, a musician and video editor, decided to record a podcast series about his life, titled ‘Unbordered’.

“While my nan was still alive he was not to be spoken of,” Mr Evans said.

“It didn’t feel right while she was alive to know more, but after Brexit I was sort of compelled to for the obvious reasons but I quickly discovered I wouldn’t be entitled to a passport. By that point, in a sense, that didn’t matter.”

He explained: “I found out my grandfather’s family moved around a lot. From Lemberg they went to Germany, then to the Netherlands and as the Nazis came to power, they were in Belgium.

“I discovered their immigration documents from this period and as late as May 1940.” In the podcast Mr Evans explains how documents from a Belgian immigration index and the Netherlands Institute for Military History revealed that his grandfather had written to Belgian authorities asking if he and his family could change their name to Lempert and become Belgian citizens “presumably hoping this would offer some form of protection. “However, this request was refused.”

Mr Lempert’s family were killed but he managed to survive by constantly “lying about his identity”, and the next record that Mr Evans found was his grandfather’s military records.

“He was able to cross from Belgium, to France, to Spain and finally to neutral Portugal and from there he was able to get to England.

“Portugal was the place to get false documents so he may have acquired a foreigner’s passport which I think was quite easy to do at the time.”

Records by this point indicated that despite not being allowed to change his name, he was giving his surname as Lempert and his birthplace as the Netherlands, which is how Mr Evans believes he was able to join RAF 320 Squadron.

“320 was a Dutch squadron and he served with them as a navigator for the rest of the war, even winning a medal for his service,” he explained.

“He had this ability to just switch who he was, he was very charming, we know that because of the affair, so they must have bought the idea he was Dutch.”

As part of the podcast, which has so far had one series, Mr Evans interviewed experts from the RAF Museum in Hendon and international lawyer Philippe Sands, whose own grandfather  was from Lemberg.

“Much of what I have found out was unknown to us until recently. We never even knew when or where he died,” he said.

A detective discovered that his remains were exhumed from their original resting place in Paris and buried again in Marseille.

“Even in death he was moving around,” Mr Evans said.