Israel's military says it has discovered thousands of hours of sickening footage showing Hamas interrogators torturing innocent Palestinian civilians in Gaza.

The harrowing videos show male prisoners with sacks over their heads, chained to floors and ceilings in painful positions.

Men writhe in agony as they are beaten with sticks on the soles of their feet.

In one distressing clip, a hooded man appears to be screaming and remonstrating with his captor.

The horrifying incidents appear to have been filmed inadvertently by CCTV cameras inside a Hamas military base in northern Gaza raided by Israeli troops earlier this year.

The footage was said to have been discovered on computers seized from the abandoned compound inside the Jabalia refugee camp. It is unclear why the men were being held.

But human rights experts have previously warned that innocent Palestinians have been kidnapped from their homes and tortured by Hamas thugs who have ruled Gaza with an iron rod since 2007.

Gay men and adulterers are among those who have been tortured by Hamas, along with political opponents and anyone accused of collaborating with Israel.

A time stamp in the corner of the footage suggests the torture took place between 2018 and 2020.

Often, the guards appear casually at ease, chatting as the abuse unfolds.

One interrogator reclines on a chair, with his arms folded behind his head, in front of a chained-up prisoner hanging from the ceiling by his arms.

Another film features a man, with a red sack over his head, chained up so awkwardly he can just about place one foot on the floor. One captor later appears to brutally choke the man.