Two companies and three individuals are alleged to have conspired to steal computing technology China does not possess.

The US Justice Department indicted two companies based in China and Taiwan and three individuals saying they conspired to steal trade secrets from US semiconductor company Micron relating to its research and development of memory storage devices.

The charges against Taiwan-based United Microelectronics Corp, China state-owned Fujian Jinhua Integrated Circuit, Co, Ltd, and three individuals mark the fourth case brought since September as part of a broader crackdown against alleged Chinese espionage on US companies.

US Attorney-General Jeff Sessions told a news conference that Chinese espionage has been “increasing rapidly”, adding “cheating must stop”. He said the government is launching a new initiative to crack down on Chinese espionage trade cases.

In addition to the criminal case, the Justice Department also filed a civil lawsuit seeking to prevent the two companies from exporting any products created using trade secrets.

FBI Director Christopher Wray said in a statement “no country presents a broader, more severe threat to our ideas, our innovation, and our economic security than China”.

The indictment alleges China was interested in gaining access to dynamic random-access memory, or DRAM, a type of technology it did not possess. Micron is the only US-based company that manufactures DRAM.

Sessions said the Taiwanese company partnered with a Chinese state-owned firm so that ultimately China could steal this technology and use it to compete against the US.

“This is a brazen scheme,” he said.

In late September, prosecutors charged Ji Chaoqun, a Chinese national living in Chicago, with acting as an illegal agent by working at the direction of a high-level intelligence officer with the Ministry of State Security to help recruit spies.

The Justice Department also in October for the first time succeeded in extraditing a Chinese intelligence officer, Yanjun Xu, to the US to stand trial for conspiring and attempting to commit economic espionage and steal trade secrets from multiple US aviation and aerospace companies, including GE Aviation, a unit of General Electric.

Earlier this week, prosecutors announced an indictment against 10 defendants, including two Chinese intelligence officers, hackers and co-conspirators, who are accused of breaking into American company computers to steal data on a turbo fan engine used in commercial jetliners.