BEIJING — One of China’s biggest animal feed producers said it had used a radio transmitter to combat crooks using drones to drop pork products contaminated with African swine fever on its pig farms, as part of a racket to profit from the health scare.

In July, the country's agriculture ministry said criminal gangs were faking outbreaks of swine fever on farms and forcing farmers to sell their healthy pigs at sharply lower prices.

A state-backed news website, The Paper, reported Thursday that a pig farming unit of Beijing Dabeinong Technology Group Co Ltd had run foul of the regional aviation authority, as its transmitter had disrupted the GPS signal in the area.

Answering questions from investors on an interactive platform run by the Shenzhen Stock Exchange, Dabeinong confirmed on Friday that its pig farming unit in Heilongjiang province had unwittingly violated civil aviation rules.

“Our unit in Heilongjiang province... to prevent external people from using drones to drop pork with African swine fever virus, violated regulations by using a drone control equipment set,” the company said.

“We broke related radio regulations, although that was unintentional,” said Dabeinong, adding that it had surrendered the equipment to authorities and was willing to accept a penalty.

The Ministry of Industry and Information Technology issued a notice on Friday calling for a crackdown on illegal manufacturers and suppliers of such equipment, saying it can only be used by public security departments, national security agencies and radio regulators.

Dabeinong has a herd of 14,000 sows at its three farms and one breeding farm in Heilongjiang. The farms in Heilongjiang were operating safely, it said, and security would be stepped up.

China, the world’s top producer and consumer of pork, has seen its pig herd shrink by 40 percent compared with a year ago, the Ministry of Agriculture and Rural Affairs said this week. Rising pork prices were a factor behind inflation’s acceleration to its fastest pace in almost eight years in November.