It’s high quality and the price is a bargain, but the risk may be too great for Chinese buyers looking for a quick profit.

Newcastle thermal coal prices have lost almost $20 a ton, or almost 19 percent, since early March, making supplies from Australia cheaper than Chinese domestic grades for the first time since April 2018, but there’s a catch. Coal from the world’s second-biggest exporter has been subject to delays since January and cargoes are sitting at China’s ports for extended periods as officials slow customs clearance.

“Cheaper Australian coal relative to domestic prices would typically induce Chinese buyers to import more,” said Dang Man, an analyst at brokerage Maike Futures Co. “But with the import restrictions in place, it’s hard to see anyone willing to take the risk.”

While demand in Asia typically weakens after the winter heating season, Chinese delays have had an impact on Australian prices, according to Clarksons Platou Securities Inc. Newcastle coal is now trading at the lowest since 2017 after custom clearance has been extended to more than 40 days, with the slowdown forecast to last till May at least.

“The ongoing uncertainty around China’s decision to delay the clearance of Australian cargoes has discouraged traders from ordering,” said Shirley Zhang, an analyst at Wood Mackenzie Ltd. “Price momentum into April is on the downward trend but it is unlikely to be a free fall.”

The delays were seen linked to a deterioration in ties between Australia and China, its largest trading partner, after Canberra banned Huawei Technologies Co. from bidding for 5G contracts as well as the introduction of anti-foreign interference laws aimed at Beijing. China has said it simply increased inspections for all coal imports and denied it singled out Australian supply.

China is the world’s largest user and producer of coal, supplementing local supplies with imports from overseas. Futures on the Zhengzhou Commodity Exchange have climbed about 9 percent this year, aided by reports of the delays as well as tougher scrutiny of mainland mines following a series of accidents. Newcastle prices closed at $80 a ton on Wednesday, down 22 percent this year.

There are other reasons for the price gap. Demand from Australia’s top customers including Japan and Korea is heading for a seasonal slowdown, while in China, miners ramping up production could further blunt the country’s appetite for overseas supplies.

“We don’t expect seaborne thermal to fall much further, as it’s simply too cheap,’’ Jeremy Sussman, an analyst at Clarksons, said by email.