An investigation has found indications of brutal mistreatment that point to possible war crimes.
ADVERTISEMENTUN-backed human rights experts say they have gathered new evidence of "horrific" torture of Ukrainian prisoners of war by their Russian jailers, and that such practices could amount to war crimes.
The Commission of Inquiry on Ukraine said on Friday that human rights violations have been widespread since Russian President Vladimir Putin ordered his troops to invade the country more than two years ago, and that civilian suffering since then only continues to mount.
"New evidence strengthens the commission's previous findings that torture used by Russian authorities in Ukraine and in the Russian Federation has been widespread and systematic," the commission said in its latest report, citing "horrific treatment" of POWs at several sites in Russia.
It said Russian forces regularly showed little regard for possible harm to civilians in their military operations, and cited incidents of rape and sexual violence against women as amounting to torture.
Relocation of children from the Kherson region in southern Ukraine to Russian-occupied Crimea did not appear to be temporary, they said, and could amount to the war crime of unlawful transfer.
The commission, mandated by the UN Human Rights Council, said it conducted more than two dozen trips to Ukraine and drew on interviews of more than 1,400 men and women over the last two years.
In one case, a former Ukrainian detainee who was not identified described having his collarbone broken, teeth knocked out and injured foot beaten, among other mistreatment, until "he begged them to kill him," the report said.
After release, he underwent 36 hospitalisations through January this year, it said.
While praising assistance from Ukrainian authorities in its investigation, the team cited a "lack of cooperation" from Russian authorities and said it received no answer to its nearly two dozen requests for meetings, access and information.
As for the Ukrainian side, the report cited "a few violations" of human rights by Ukrainian authorities against people suspected of collaborating with Russia.