Palestinian security forces regularly torture prisoners and arrest political opponents “to crush dissent” in both the occupied West Bank and Gaza, Human Rights Watch (HRW) said Tuesday.

A new report said both the Western-backed Palestinian Authority (PA) and its rivals in Hamas make systematic use of torture and widespread arrests which could amount to crimes against humanity.

HRW called on Britain, the US, and the EU cut off funding for the PA’s security forces until they stop torturing detainees and investigate officers of accused of abuse. The group also called on Qatar, Iran, and Turkey to halt their funding for Hamas.

Both the PA and Hamas security forces denied to HRW that they practice torture and said they investigate all allegations of abuse.

Tom Porteous, deputy programme director at HRW, said those claims were not accurate. “Calls by Palestinian officials to safeguard Palestinian rights ring hollow as they crush dissent,” he said.

In one of the most disturbing allegations, HRW said PA security forces arrested a 32-year-old civil servant and tied a cord around his genitals for eight hours, causing them to “swell and turn blue”.

The man said his captors kept him a small room known as “the closet”, roughly 60cm by 60cm, where he struggled to breath. He said he was kept in the room for 22 hours a day for 22 days in a detention facility in Jericho in the West Bank.