A fighter jet pilot or anti-air missile operator could, therefore, select fast-moving targets on a touch screen with unprecedented speed and accuracy, according to two mainland researchers informed about the study.

This makes China’s stealth fighter J-20 a candidate to use it, said the two researchers, who declined to be named.

Shumin Zhai, a lead scientist in Google’s artificial intelligence (AI) team, was named on Friday as one of the authors of the research paper.

Google confirmed its involvement but denied a link to the military.

“This paper addresses a very general research question in user experience design of how people interact with moving items on a touch screen,” said a Google spokesperson. “This paper is simply not about military applications.

“There is nothing in this paper that refers to a military application. Research like this is key to improving finger or stylus-based navigation in any app.”

Google denied it had contributed AI technology to China. “It uses long-existing statistical modelling techniques, not AI or deep learning models,” the spokesperson said.

China has put a 25-inch touch screen in its J-20 jet, the biggest of its kind in the world, according to previous state media reports.

The screen size is more than 50 per cent larger than the touch screen of the United States’ F-22 stealth fighter jet and 35 per cent larger than that of the US’ F-35.

The J-20’s touch screen can display airborne weapon configuration, engine status, airborne radar search, enemy-friendly targets, navigation path and complete flight attitudes.

They need to follow the target continuously while planning the timing for selecting it. The high demands on eye-hand coordination could lead to mistakes during combat. There have been reports that F-35 pilots still relied on the traditional cursor for target selection.

Some solutions have been proposed, such as reducing targets’ moving speed and making the dot larger on screen, but these can distort the display’s consistency.

Google came under fire from employees last year after it came to light that the tech giant was secretly building a censored version of Google Search for China.

The Chengdu J-20, also known as Mighty Dragon, is a single-seat, twinjet, all-weather, stealth fifth-generation fighter aircraft developed by China’s Chengdu Aerospace Corporation for the People’s Liberation Army Air Force (PLAAF).

The J-20 is designed as an air superiority fighter with precision strike capability; it descends from the J-XX program of the 1990s.