Monitoring company Golos said they had received floods of reports of vote-rigging but there was little it could do through official channels.
The ruling United Russia party, which is backed by Vladimir Putin, is on track to win 343 of 450 seats in Russia’s lower house of parliament.
With 90 per cent of the vote counted, the pro-Kremlin party had 54 per cent of the vote for the 225 seats chosen nationwide by party list, the Central Elections Commission said.
The three parties who were the next most popular – the Communist Party, The Liberal Democrats and the Just Russia Party – all support Mr Putin.
However, there have been multiple reports of voting fraud and videos have surfaced of apparent ballot stuffing.
One video shows an official appearing to take a pile of ballots and shoving them into the voting box while another person seems to stand guard.
Election monitoring groups received reports throughout the day of voting fraud.
Monitoring company Golos said they had received floods of reports of vote-rigging but there was little it could do through official channels.
“We don’t have any way to fight it through law enforcement agencies or through courts but we fight violation through attracting public attention,” Roman Udot, co-chair of Golos told the BBC.