"I have no official documents that Russian law enforcers acted in a manner that ran contrary to Russian legislature," Sergei Prikhodko said.
He added that if some facts appeared proving that the detention was illegal they would all be thoroughly investigated in line with Russian legislation.
Last week Prikhodko told journalists that antiglobalists should not go to Russia's second city during the summit of Group of Eight leaders on July 15-17 if they were intent on causing trouble.
Violence has marred G8 summits in the past, particularly the 2001 meeting in Genoa, when demonstrators entered into running battles with riot police and one man was killed.
Prikhodko also said that Russia was glad that its style of communications with NGOs was used by other colleagues, referring to a meeting earlier in the day between U.S. President George Bush and representatives of Russian NGOs.
"We are glad that this style of communication is used by other colleagues of the Russian president," Prikhodko said. "It is probably the right way."
He added that, "With the beginning of Russia's chairmanship of the G8, unprecedented work has been conducted with NGOs."
The leaders of Germany, France, the United Kingdom, Italy, Canada and Japan are expected to arrive in Russia's second city Saturday.
