SHANGHAI — D.J.I., the popular drone maker, stands as a symbol of China’s growing technology prowess. Its propeller-powered machines dominate global markets and buzz regularly over beaches, cityscapes at sunset and increasingly, power plants and government installations.

Now D.J.I. is fighting a claim by one United States government office that its commercial drones and software may be sending sensitive information about American infrastructure back to China, in the latest clash over the power of data in the growing technological rivalry between the two countries. It also shows how consumer technology companies have become increasingly central to debates about national security.

The company, formally named Da Jiang Innovations Science and Technology Company, put out a statement this month contesting the allegations made in a dispatch from United States customs officials. The memo, from the Los Angeles office of the Immigration and Customs Enforcement bureau, was dated in August but had begun to circulate online more recently.

It said officials had “moderate confidence” that the D.J.I.’s commercial drones and software are “providing U.S. critical infrastructure and law enforcement data to the Chinese government.” It cited what it called a reliable source, who it did not identify, in the drone industry “with first and secondhand access.”