A video showing a man who was forced to strip naked being mistreated by riot police has stoked protesters’ anger in Ukraine.

Before putting him in their van near Kyiv, they made the detained demonstrator undress.

Wearing only socks, he was forced to stand in the snow while they took pictures.

After being made to pose holding a piece of metal tubing, he was finally allowed to get onto the bus. As he did so, an officer kicked the man in the leg.

A video showing the incident was posted on the website of Ukrainska Pravda newspaper.

Faced with video proof of this brutal episode, police apologised for what they called “inadmissable action” and said they were launching an investigation.

Daytime temperatures in Ukraine’s capital on Thursday when the video was shot were minus 10 degrees Celsius.

It does not appear to be an isolated incident.

There are reports of others facing similar treatment, as well as claims of abductions – including from a hospital – torture and suspicious deaths.