The gaming company said a group of staff were being questioned, with the Department of Foreign Affairs working to confirm whether Australians were involved.
The Australian Financial Review reported that at least 18 were being held, including three Australians who are part of the group's sales and marketing team in China. One was said to be a senior executive.
"Crown believes that a number of our employees in China are being questioned by local authorities," the company told the newspaper.
"At this time we can provide no further details."
The Australian government said it was aware of the issue and "consular officials are seeking to confirm these reports with the relevant Chinese authorities".
It is not clear whether any charges have been laid or why the employees are being questioned.
Crown operates casinos across the world, including in Macau, where revenues have been hit hard by a Chinese corruption crackdown which has driven away many high-rollers.
Graft has become endemic in China and President Xi Jinping launched a much-publicised drive against it after he came to power in 2012.
Packer, who is engaged to pop diva Mariah Carey, owns 53 percent of CrownResorts but resigned as chairman in 2015.
