Sportswear brand has been targeted by China's influential state television broadcaster for alleged false advertising.
The company was accused of selling sneakers in China that didn't have the "Zoom Air" cushion in the shoe as advertised. State media also alleged Japanese retailer Muji was selling food in its stores from areas of Tokyo with high levels of radiation.
China Central Television made the allegations in an annual program that airs on World Consumer Rights Day. In the past, the show has gone after major brands, including Apple, McDonald's, Nikon and Volkswagen, typically forcing the companies to apologize and take corrective action to regain public confidence.
The show also reflects the growing influence of China as the world's biggest consumer market of 1.4 billion people.
Accusations of wrongdoing from Chinese state media can have a big impact on foreign companies in China. In 2014, Japanese camera maker Nikon was accused of selling defective cameras and failing to address customer complaints. The company later apologized and accepted cameras for repair and maintenance, even though the original warranty period had ended.
Volkswagen recalled nearly 400,000 vehicles after the 2013 consumer rights broadcast. State media have previously also gone after firms including British drug giant GlaxoSmithKline for price-fixing, bribery and poor quality products. GSK saw its China sales fall, and was even placed under government investigation.
China is an important market for both Nike and Muji. In 2016, Nike saw its China sales grow 27 percent, for example.
Shares of Japanese firm Ryohin Keikaku, which owns the Muji brand, fell around 3 percent Thursday morning in Tokyo. Nike dropped as much as 0.9 percent in New York trading on Wednesday, before closing up 0.7 percent.
Nike and Muji didn't immediately respond to a request for comment.