A Ukrainian security service officer stands next to a monitor showing a Russian army major detained at the weekend

Ukraine’s spy agency, the SBU, is systematically rounding up and torturing suspected rebel sympathisers, the United Nations has told The Times.

Ivan Simonovic, UN assistant secretary-general for human rights, said that in some areas Kiev’s “disregard for human rights” had become entrenched and systemic and needed to be urgently addressed.

The UN report documents hundreds of cases of illegal detention, torture and ill-treatment of detainees — both by pro-Russian armed groups and by government agencies.

It draws attention to prisoner abuse and murders by pro-Russian rebel groups, but also exposes the scale and brutality of Ukraine’s government-backed torture programme for the first time, as well as the existence of five secret government detention centres.

Mr Simonovic described one instance when a suspect was picked