China's top antitrust authority said on Friday it has already made "important" progress in its probe into three dominant chipmakers, including Samsung, over possible price fixing.

Wu Zhenguo, director of the anti-monopoly bureau under the State Administration for Market Regulation, said the agency has obtained and screened evidence from relevant companies and their downstream partners.

The comments came after the authority started an investigation in May on possible price-fixing behavior by South Korea's Samsung, SK Hynix, and US-based Micron over the last few years.

The next step is how to define the case itself, how to address their market dominance as well as the companies' relevant practices, Wu said at a press briefing.