Trade Minister Simon Birmingham says he is deeply troubled by reports China has banned Australian coal.

It follows a string of other Australian exports that China has hit with trade sanctions.

Dozens of ships carrying Australian coal have been stranded off the coast of China for months due to supposed environmental problems.

But overnight, a Chinese state-owned media outlet reported power plants had been directed to stop taking Australian coal.

The Australian government has not been notified of the ban.

“We see these reports and obviously are deeply troubled by them,” Senator Birmingham told ABC radio on Tuesday.

“They, if true, would indicate discriminatory trade practices being deployed by Chinese authorities and we would urge them to rule that out swiftly.”

It’s the latest crackdown by China on Australian goods, which has so far hit consumables including beef, wine, barley and seafood, plus timber.

Senator Birmingham said the Australian government was close to finalising a complaint to the World Trade Organisation over Chinese tariffs imposed on barley.

“We are well prepared in terms of the analysis we have undertaken to mount that case,” he said.

Australian exporters heavily reliant on China have been brought to their knees by deteriorating trade ties.

Senator Birmingham said he could understand if Australian exporters looking to do business in China were more sceptical about entering into contracts.

China is Australia’s most valuable export partner and in recent years has taken the majority of coal leaving Aussie shores, in an industry worth more than $10 billion a year.

There are suspicions the trade tensions have grown from China’s grievance list spanning Australia’s foreign investment rules, banning Huawei from the 5G network, and the push for an inquiry into the origins of COVID-19.