While Dalian only takes about 2 per cent of Australia's coal exports, such a ban would mark a deterioration in often strained relations between the key trading partners.
The Australian dollar fell as much as 1.1 per cent, the most in two weeks, to around 0.7086 on Thursday after the Reuters report.
Meanwhile, China's biggest traded mining company, China Shenhua Energy Co, rose more than 4 per cent.
Asked directly about the report on Thursday, foreign ministry spokesman Geng Shuang told reporters in Beijing that China examines imported coal to protect the environment.
He didn't say whether China was targeting Australia specifically. Trade Minister Simon Birmingham said Australia's ambassador to Beijing was seeking to "urgently clarify" the veracity of the report.
China, which has a history of using trade as leverage, has been seeking to counter resistance in several nations to using Huawei in 5G networks.
Its ambassador to Canada this week warned that excluding the company will have repercussions. New Zealand, which has also barred Huawei, has sought to downplay concerns that China is now turning a cold shoulder.
- Additional reporting from Bloomberg