Robert became emotional during filming

Judge Robert Rinder discovers how the parents and five siblings of his Jewish grandfather, Moishe Malenicky, died at the hands of the Nazis in an upcoming episode of Who Do You Think You Are?

The heartbreaking episode will see the former Strictly contestant travel to Piotrkow in Poland, where he’s taken to the spot where his grandfather’s family would have been taken to their deaths during the Holocaust.

“Just the most staggering thing of passing on a speeding train, your family gone and then you go back to your house and you’re alone.

“It’s impossible to fathom for my grandfather what that must have been like – to come back to nothing,” said Robert.

A BBC source told The Sun about: “Robert already had some knowledge about his family’s history but discovered the full extent of their treatment during filming.”

Robert’s grandfather, who was later sent to a concentration camp in Germany, was brought to the UK at the end of the war.

Robert has previously spoken about his granddad’s experiences during the war, once telling The Mirror: “My grandfather did not speak of it often but there were dark shadows, poisonous drips of stories, that were always in my psyche.”

The popular star last month clocked up his 1,000 case on his hugely popular ITV show.

Not Going Out star Lee Mack and former Coronation Street star Michelle Keegan are among the people taking part in the new series of Who Do You Think You Are?, which will begin later this year.

Main pic: Joanne Davidson/Silverhub/REX/Shutterstock