French authorities on Friday said tech giant Apple has agreed to pay €25 million ($27.4 million) for failing to inform users that software updates to older iPhone models could slow down the device, according to French media.

Le Parisien reported it was the highest fine for fraud ever imposed by the consumer watchdog.

The crackdown comes two years after Apple admitted its iOS software slowed down the performance of older phones — in particular, devices with shorter battery life.

An inquiry was opened in January 2018 after the Halt Planned Obsolescence (HOP) association filed a complaint.

"IPhone owners were not informed that installing iOS updates (10.2.1 and 11.2) could slow down their devices," the DGCCRF anti-fraud agency said in a statement.

"This is a historic victory against scandalous ready-to-rubbish practices, for consumers as well as the environment," HOP co-founders Laetitia Vasseur and Samuel Sauvage said to AFP.

The group added it will consider filing claims for additional damages on behalf of iPhone clients.