Samsung has sold over five million Galaxy Note II products, setting a cumulative global sales record for three months.
Released five months ago, the device passed three million sales earlier this month, representing over two million sales during November alone.
The news follows a company audit of Samsung's Chinese suppliers, which found illegal labour practices including long hours and excessive overtime.
After conducting a four week review of 105 suppliers in China, Samsung was responding to claims from New York-based labour rights group China Labor Watch over child labour and "inhumane" working conditions.
But the South Korean company says its audit team found no evidence of child labour, but plans to eliminate illegal overtime by the end of 2014.
The company will also audit 144 more suppliers across the country.