The IDF on Monday night confirmed the death of Nadav Popplewell, 51, from Nirim, while in Hamas captivity.
His death was announced along with the deaths of Haim Perry, Yoram Metzger, and Amiram Cooper.
Popplewell was taken hostage with his mother, Channah Perri, who was released on November 24. His brother Roi, age 54, was murdered on October 7.
His sister, Ayelet Svalitzky, has been active campaigning in London for his release since October 7.
Popplewell held British and Israeli citizenship. He was born in Wakefield, Yorkshire, and made aliyah over 20 years ago.
He was an avid reader and a fan of science fiction. He enjoyed playing bridge at the kibbutz and watching TV series.