The group, which represents 46 national rights committees, said the other seven leaders should address the plight of political prisoners. It said it was "appalling" that people had been imprisoned in Russia after politically motivated trials.
In a joint statement with the Moscow Helsinki Group, it called on G8 leaders to bring up the issue of rights violation and corruption in Russia's North Caucasus. It said the "war on terrorism" had become a "pretext for the continuing abuse of human rights" in the region.
It also noted the lack of openness in the government's handling of emergencies, including terrorist attacks.
It also said Putin's G8 partners should address restrictions on the media and a restrictive new law governing the activity of nongovernmental organizations.