Palestinian Islamist militant group Hamas released a video on Tuesday purporting to show an Israeli citizen being held captive in the Gaza Strip, the first such images of the man since his capture seven years ago.
As Egyptian-mediated negotiations between the sides on such a deal have lagged, the move appeared to be a Hamas attempt to pressure Israel for a prisoner swap.
The 39-second video showed a conscious man lying in a bed with an oxygen mask on his face, and ended with a close-up on what appeared to be an Israeli ID card bearing the name and photo of one of the civilian captives, Hisham al-Sayed.
A TV screen next to him appears to show news images from an economic conference in Qatar this month.
Hamas did not provide any details about the captive's condition after saying on Monday that his health had deteriorated.
Israeli Prime Minister Naftali Bennett said a video of a sick man was a reprehensible and desperate act and that Hamas was violating international conventions by holding a civilian who he said was suffering from a mental disorder.