UEFA has announced that an incident on Oct. 20 when four black fans were attacked during Dynamo Kiev's 0-0 draw with Chelsea last week will be subject to an investigation.
At least two of the victims of the attack were hospitalised, with one stabbed as he tried to make his exit from the NSK Olimpiyskiy Stadium.
European football's governing body opened disciplinary proceedings last week, charging Kiev over racist behaviour, crowd disturbances and having blocked stairways but further investigation is needed.
A UEFA statement read: "The UEFA Control, Ethics and Disciplinary Body (CEDB) has decided to appoint a UEFA Ethics and Disciplinary Inspector to conduct an investigation with regard to the facts of the present proceedings.
"The date of the CEDB meeting will be determined at a later stage.''
Piara Powar, the executive director of the anti-discrimination group FARE (Football Against Racism in Europe) Network, told Press Association Sport: "It's quite clear the attack that took place. It's documented in video, and subsequently other videos and still photographs have come to light.
"There's no doubt this was a racist attack. From what we've now seen was it was a racist attack that was accompanied by people talking about 'white power.'
"It was perpetrated by the far-right fans in the Olimpiyskiy Stadium."