Minimalistic door handles became a signature feature of electric vehicles (EVs), but the controversial designs are now at the centre of China's biggest car recall, affecting more than 4 million vehicles.

The recall, which includes 2.98 million Chinese-made Teslas, follows safety concerns that the hidden door handles are difficult to locate and open in emergency situations.

Other brands affected by the recall include Chinese carmakers XPeng, Xiaomi and Geely.

The recalled vehicles will have a warning label affixed to the interior door and receive a software update that automatically lowers the windows in a crash.

The designs have come under scrutiny after two fatal crashes in China involving Xiaomi EVs, in which power failures were suspected of preventing the doors from opening.

Tesla said in a statement on Friday that it was recalling some of its Model 3, Y, S and X vehicles due to door handles that are "difficult to identify and operate because their colour is similar to the interior trim".

"In extreme situations such as a severe collision causing the vehicle's low-voltage system to fail, this could hinder occupants from quickly opening the doors to escape and impede rescue efforts by those outside the vehicle, posing a safety hazard," it said.

Tesla said it would place warning labels on the recalled vehicles and issue a software update to automatically lower a vehicle's windows after a collision.

The BBC understands that carmakers have not yet notified authorities of any plans for a similar recall in the US.

The BBC has contacted Tesla, XPeng, Xiaomi and Geely for comment.

The use of hidden handle designs has "snowballed" since Chinese brands quickly copied the "sleek" look of Tesla's Model S sedan in 2014, said Tu Le, the managing director of the consultancy Sino Auto Insights.

The use of warning labels and a software update is more of a "band-aid" than a lasting solution for the issue, he added.

In February, Chinese authorities announced a ban on hidden door handles.

Under new rules due to take effect on 1 January 2027, cars will only be allowed to be sold in China if they have a mechanical release on both the inside and outside of their doors.

Tesla's door handles were also involved in a probe by US safety regulators after reports that they suddenly stopped working, leaving children trapped in the cars.

In July, the US National Highway Traffic Safety Administration suggested creating a new formal safety standard for all carmakers.

The agency told the BBC that it is reviewing whether it will require emergency door-exit systems in vehicles.