A Ukrainian opposition activist who went missing more than a week ago has been found badly beaten, saying his captors cut off his ear and drove nails through his hands.

Dmytro Bulatov, a 35-year-old activist from the Avtomaidan group that organised protests against President Viktor Yanukovych, stumbled into a village outside Kiev more than a week after his wife first reported him missing.

Speaking with Channel 5 television on Friday, Bulatov said his captors blindfolded and tortured him before dumping him in a forest.

"My hands... they crucified me, nailed me, cut my ear off, cut my face," said Bulatov, his face swollen and covered in caked blood. "Thank God I am alive."

"I can't see well now, because I sat in darkness the whole time," he said, still wearing his blood-stained clothes.

The activist was eventually able to make contact with his friends after wandering through the forest to the nearest village, a fellow activist identified only as Yuriy told Channel 5.

"He's alive! All of these days he was tortured, cut, crucified," opposition MP Anatoliy Grytsenko wrote on his Facebook page after speaking with Bulatov.

Bulatov disappeared and stopped picking up his cell phone on January 22 as the two-month protests in Ukraine escalated into deadly clashes with police.

His disappearance caused great concern because it followed other cases of apparent kidnappings of prominent activists from the opposition protests in central Kiev.

One of the activists, Yuriy Verbytsky, was found dead in the forest while another, Igor Lutsenko, survived a severe beating and was hospitalised.

Avtomaidan is a loose group of drivers who have organised protest motorcades near Yanukovych's sprawling country estate in Mezhygirya outside Kiev.

Its members have come under immense pressure from the authorities and some of its members have gone into hiding or left the country.