Beijing: China's crackdown on coal imports has become significantly harsher, with Australian and Mongolian coal being particularly targeted for inspection on "environmental" grounds.

Inspectors recently rejected 182 trucks carrying 19,540 tons of Mongolian coal, the biggest coal turn-back in years.

And Australian coal continues to suffer long delays at Chinese ports, with coal industry analysts who spoke to The Age and The Sydney Morning Herald saying environmental inspections had been significantly stepped up this year.

Inspection and quarantine workers take samples of imported coal at a port in Rizhao in eastern China's Shandong province in 2010. Credit:AP

The customs office in Wulate, in Inner Mongolia, ran laboratory testing, including radiological and phosphorous testing, and rejected the Mongolian coal for "exceeding the standards stipulated in the Interim Measures for the Quality Management of Commerical Coal", according to China News Service.