Tetyana Chornovil, 34, was chased down by car and beaten shortly after midnight on Wednesday, hours after posting pictures on her blog of a country home she said belonged to Interior Minister Vitaly Zakharchenko.
The attack threatened to breathe new life into more than a month of opposition protests in the capital, Kiev, over a decision by the government in November to spurn a landmark pact on closer ties with the European Union and turn instead to former Soviet master Moscow.
In a video statement posted on the website of the Interior Ministry, Mykola Chynchyn, the head of the main investigations department, said:
"In the course of the investigation it was established that the detained had been in close contact with members of the party UDAR."
UDAR, or Punch, is led by heavyweight boxing champion Vitaly Klitschko, the most prominent of a troika of opposition leaders who have seized on the outcry among many Ukrainians over the government's move away from Europe.
Chynchyn also alleged ties between one suspect and a lawmaker from the opposition Fatherland party of jailed former Prime Minister Yulia Tymoshenko.
Chynchyn said nothing about the possible motive for the attack.
With tents and braziers against the winter cold, a core of hundreds of protesters is occupying Kiev's central Independence Square behind barricades.
The protests, however, are showing signs of losing steam, with turnout at weekly mass rallies down since the height of the backlash in late November and early December when hundreds of thousands packed downtown Kiev.
Chynchyn said the police investigation had also established links between one of the detained and the head of a criminal gang "with whom the Klitschko brothers had closely cooperated", without offering any details.
Klitschko, whose brother Vladimir is also a heavyweight boxing champion but is not involved in politics, said he would sue for libel.
"Instead of conducting an objective investigation and finding who really ordered and carried out the beating of Tetyana Chornovil, the ministry of Zakharchenko turns to provocation and effectively tries to conceal the criminals," he said in a statement issued by Udar.
Vitaly Yarema, a member of Tyomshenko's Fatherland party, accused the Interior Ministry of trying to exploit the assault for political ends.
Chornovil, an opposition journalist and activist who had taken part in the anti-government protests, has waged a campaign to document the opulence of the political elite under President Viktor Yanukovich, most famously by scaling the walls of the president's own residence in a park near the Dnieper River.
Yanukovich condemned the attack on Chornovil and urged police to find the perpetrators.
The assault, which left Chornovil hospitalized with a bloodied and badly bruised face, was the latest targeting activists involved in the opposition protests.
Hundreds of opposition protesters rallied at the Interior Ministry on Thursday calling on Zakharchenko to resign.
Opposition supporters have accused authorities of either direct involvement, or of creating a climate of impunity that allowed the attack to take place.
The United States condemned what it said was "an emerging pattern of targeted violence" and said it would follow the case.
The opposition plans to rally supporters on Sunday and again on New Year's Eve.
Source: Yahoo News