Lisa Kudrow has uncovered a shocking family connection to the Holocaust while filming the U.S. version of Who Do You Think You Are?

Lisa Kudrow (46) broke down in tears after she discovered her great-grandmother was murdered by the Nazis during the Second World War, Daily Mail reports.

She was on a mission with researchers from the programme – originally developed by the BBC – to find out what happened to Mera and where she was buried. When Kudrow was a child, her grandmother told her Hitler killed her mother but the actress wanted to find out more about her ancestor.

The Friends star visited the memorial to her great-grandmother and the other victims who were killed by the Nazis