Green, an influential Twitter account with a track record of revealing insights about Tesla from software analysis, made an about some of the company's latest software that has piqued the interest of a European car safety organization.
Green tweeted that Tesla recently added the name of an Australian and Asian vehicle testing ground to its software. There are other vehicle testing grounds also listed in the code, he said, located in Europe, China and Korea. Important tests that benchmark vehicle safety happen at these sites, which have government and industry support. This curious inclusion of testing ground names in the code, Green suggests, could indicate that Tesla vehicles are designed to perform differently in testing grounds. That could undermine the quality of test results.
Now Euro NCAP, Europe's government-backed organization that evaluates vehicle safety, is investigating Tesla following this suggestion.
So far regulators have found no evidence of any wrongdoing, Euro NCAP program director Aled Williams told CNN Business in an email last week. (NCAP stands for new car assessment program.) The agency performs tests and assigns new vehicles a safety rating from zero to five stars. It's highly respected in Europe.
"The integrity of its star-rating scheme is of utmost importance to Euro NCAP and we will continue to do all we can to ensure the rating reflects the safety which consumers can expect from their vehicles," Williams said. "So far, Euro NCAP's investigations have not revealed any evidence of an attempt to 'cheat' the tests by Tesla."
Euro NCAP said shortly after Green's tweets that it was investigating the findings and seeking more information from Tesla.
Tesla did not respond to a request for comment on the investigation.
The organization has examined Tesla's software updates to test vehicles and not found any fault, Williams said.
Williams said the investigation wasn't uncommon as, when it has reason to do so, it has looked more closely into vehicle performance to verify findings. He said the Tesla investigation has been more high-profile than others.
Green had mentioned that geofencing can be used to activate or deactivate a feature in a certain location. Tesla, for example, has restricted its driver-assist system that it calls "full self-driving" in part of Toronto.
Euro NCAP has not found evidence that Tesla used geofencing to identify when a vehicle is at a test location and alter its performance.
"It is possible that GPS location is used to identify that the car is at a specific test track," Williams said. "It's one of the possibilities we put to Tesla and they absolutely deny that this is done."
Williams said that the GPS location of a vehicle would be known once it is turned on.
He also said that Euro NCAP has been told that the software code references to particular test programs like the Australian and Asian one -- known as ANCAP -- are used only to identify the region for which the car is configured.
"Different regions (such as Europe, Australasia etc.) differ in terms of legislation as well as road conditions/markings etc.," Williams wrote. "The recent addition of ANCAP to the code of Model Y coincides with the start of sales of that vehicle in Australasia."
Green, the influential Twitter account, told CNN Business via Twitter DM that this explanation seemed strange given that Japan, which has unique markings and signs, is not listed in the software.
Euro NCAP's Williams declined to comment on this inconsistency. Tesla did not respond to a request for comment.
There's still work to do in the investigation, Williams said. They're looking into confirming that they can replicate the results of their official tests.
Tesla's Model Y SUV had received the highest grade of any vehicle in Euro NCAP's safety test that ranked driver-assist systems in September.
Though there is no indication that Tesla software is interfering with any testing, It's not unheard of for an automaker to use software to manipulate a test. Volkswagen edited software in as many as 11 million vehicles so that emissions of nitrogen oxides were much lower in tests than on the road, allowing it to meet clean air standards.
The fallout was damaging for VW as the automaker recalled millions of vehicles at an expense of $7.3 billion. VW's CEO lost his job.