The Israeli army claims it has found a Hamas tunnel inside Gaza's biggest hospital, al Shifa.
The latest footage posted by the IDF shows the view inside an underground tunnel in the eastern edge of the hospital.
A professor specialising in underground warfare says she believes the tunnel seen in the video is "consistent with Hamas tunnels".
Hamas has repeatedly denied Israeli claims that it's used the medical facility for its operations, while Israel claims it is home to the group's headquarters.
The "operational tunnel shaft" in the IDF video posted on Sunday is located just over 40 metres away from the Surgery Building. It was located using the distinctive white and grey stripes seen in the background of the video.
It's also around 50 metres from the chest and dialysis department and close to the eastern perimeter of the hospital grounds.
The hole was underneath a white temporary building spotted in a previous video posted by the Israeli army last week shown in the screenshot below.
The footage which the IDF says was taken on Friday and released on Sunday is an edit of two separate videos posted on the army's Telegram channel. The alleged Hamas tunnel is approximately 1.5m wide.
Based on historical satellite imagery on Google Earth, we found the white building was there in May 2022 but not there before March 2021.
We don't know what the building was used for.
While we are unable to verify who built the structure shown and what it was used for, there are some identifiable features inside the tunnel.
At the surface of the alleged tunnel shaft, a long vertical concrete column is seen. As the camera descends you also see a long metal pole and spiral metal staircase.
As it reaches the bottom, the camera is taken through to a narrow concrete corridor with an arched top at the end of which the IDF says there is a metal door.
The Israeli military claims the tunnel is 55 metres long and 10 metres deep using a three-metre ladder and spiral staircase for another seven metres. It says it believes the tunnel connects inside the hospital to the outside. Sky News is unable to verify this claim.
Videos 'consistent' with Hamas tunnels
Dr Daphne Richemond-Barak, an expert on underground warfare who teaches at Reichman University in Israel, said the IDF videos are "consistent" with Hamas tunnels.
She told Sky News: "What we saw in those pictures were very typical, very classic of the Hamas tunnels. I'm comparing it to the tunnels of Hamas I have personally been in which were the cross-border tunnels which are different, more basic and rudimentary.
"I've also compared the IDF-released images to Hamas's own pictures and videos that have been filmed inside the tunnels. What I saw from this video was very typical of that, so there is this big cylinder hole with a very elaborate cemented contour, then it goes into something much more narrow and tight, then it goes into a dark alley... The images we've seen so far are very consistent with what we know for years has been the work from Hamas."
Dr Richemond-Barak also says she has "no doubt that this is only one little piece of what will eventually be exposed, but it takes a lot of time".
Same tunnel different video
Israeli forces seized the hospital last week to search for what they said was a Hamas tunnel network built underneath.
Hundreds of patients, medical staff and displaced people left al Shifa at the weekend, with doctors saying they were ejected by troops and Israel saying the departures were voluntary.
But the video posted on Sunday was not the first piece of footage of the alleged tunnel - the IDF released-video and an image of the same tunnel last Friday. However, that footage offered a limited view at the surface of the tunnel - which was littered with concrete, wood and sand.
Sky News is unable to independently verify claims made by the IDF about what the tunnel was used for and who built it.