Zhuzhou Rubber, a unit of Chinese state chemical giant ChemChina, said it “is mainly engaged in manufacturing sounding balloons of natural latex in compliance with all applicable laws and regulations”.

“Our products are used for daily weather forecasting by weather stations, and do not have any connection with the so-called and reported US balloon incident,” it said in a statement posted on ChemChina’s website.

A suspected Chinese surveillance balloon, which Beijing denies was a government spy vessel, flew over the US and Canada for a week before being shot down off the Atlantic Coast on US President Joe Biden’s orders.

China has called the US handling of the balloon incident “hysterical” and an “absurd” act that violated international norms.

The manufacture of weather balloons in China is dominated by Zhuzhou Rubber, which makes 75% of high-altitude balloons used by the China Meteorological Administration, the country’s regulator of state-owned firms said in a statement last year.