IDF Spokesman Rear Adm. Daniel Hagari in a press conference airs footage showing Hamas leader Yahya Sinwar in a tunnel in southern Gaza's Khan Younis.
He says the footage is from October 10, three days after the war began.
The footage shows Ibrahim Sinwar, the Hamas leader's brother, leading Yahya Sinwar along with his wife and children, through the tunnel passage.
Hagari says that earlier this month troops detained close relatives of senior Hamas military commanders, and of Sinwar.
He says that among those detained are the father of Rafa’a Salameh, the commander of Hama's Rafah Brigade, and the son of Husni Hamdan, another senior Hamas commander.
"In the Shin Bet interrogations they are providing us with a lot of intelligence," Hagari says.