No political pretext has been confirmed in the attack.
The National Police in Ukraine have classified the attack on the Kremlin's former political prisoner Volodymyr Balukh as robbery.
That's according to a statement by Kyiv Police Department.
"The information collected into this fact has been filed in the Unified Register of pre-trial Investigations. The Investigation Department of the Dnipro District Police Unit of Kyiv has started criminal proceedings under Part 4 of Art. 187 (robbery) of the Criminal Code Of Ukraine," the statement says.
The article envisages a prison term of eight to 15 years with confiscation of property.
Assault on Balukh: background
Former Russian political prisoner Oleg Sentsov said Volodymyr Balukh has been assaulted in Kyiv overnight Tuesday, September 8. Meanwhile, September 7 marked a year since his successful return to Ukraine after he was released from a Russian prison.
Sentsov said Balukh was found this morning, with his arm and collarbone fractured.
Read alsoUkrainian political prisoner Balukh testifies about tortures in Russia (Video)