The J-20, the People’s Liberation Army’s fifth-generation fighter jet touted as China’s answer to the United States’ F-35, could have been designed and developed with technology stolen from the US, according to a senior US official.

This accusation was another in a long list of technology and proprietary designs that Beijing allegedly stole and used to reverse-engineer its own weapons.

For instance, the sensor system on the J-20, which is visible on the fuselage in some high-resolution photos handed out by the Chinese military, looks “awfully similar” to the Lockheed Martin Electro-Optical Targeting System on the front of the F-35 Lighting II, according to a report in the National Interest magazine, based on another piece run by the Task & Purpose, a military and veteran-focused digital platform, in August 2018, which described a cyber-espionage incident that sounded like the heist film Ocean’s 11.

The US’s F-35 stealth fighter is allegedly the blueprint for China’s version of the stealth fighter. Photo: Handout

In 2007, Lockheed Martin reportedly found Chinese hackers stealing technical documents related to the F-35 program, a serious online security breach revealed by Edward Snowden, a CIA operative-turned traitor who fled to Hong Kong and then Russia in 2013.

A similar theft occurred again in 2017, when Chinese hackers allegedly went after Australian F-35 defense contractors, getting even more info on the cutting-edge fighter.

In 2014, a federal grand jury indicted a Chinese national for a computer hacking scheme that involved the theft of trade secrets from Boeing’s C-17 military transport aircraft. The individual also was accused of working with two co-conspirators based in China to steal military data about the F-22 and F-35 jets.

The sensor systems on the Chinese and US fighters share some striking similarities in shape and placement and differ substantially from those mounted on Russia’s Su-57, despite the fact that the J-20 is most likely powered by the same two AL-31F hypersonic engines that propel the Russian fighter.

Also, parts of the design of the J-20 appear to mimic the F-22 and its stealthy curves, even though the J-20 lacks all-aspect stealth and may be tracked by some advanced radars.

Earlier last month, during a visit to Ukraine, former US National Security Advisor John Bolton claimed China stole F-35 technology to make a fifth-generation stealth fighter.

“It looks a lot like the F-35, that’s because it is the F-35. They just stole it,” said the anti-China firebrand.

Some US papers say the FC-31 fighter still being developed in China could be an “F-35 knockoff.” A model of the plane appeared at the Paris Air Show in June, and Chinese theft of sensitive US military technology is still a huge problem, says defense analysts.

Hacking over the years is one of the reasons China has been able to narrow the gap with the US in advanced missiles, drone technology and even stealth aircraft.

“What Beijing has been very good at is targeting US defense contractors, getting into their computer systems through various types of essentially cyber warfare and stealing the designs of some of America’s best military assets,” Harry Kazianis, director of defense studies at the Center for the National Interest, a think tank founded by former President Richard Nixon, told CNBC.

Read more: China’s J-20 deployed as Taiwan waits for F-16s

Stealth wars: China’s J-20 vs. USAF’s F-35