France's technology watchdog said on Wednesday it is investigating an iPhone feature that tracks and stores data on its user's movements, without the user's knowledge or consent.
Regulators in South Korea announced earlier on Wednesday that US technology giant Apple would be fined over the iPhone location tracker, as it violated user privacy rules.
British researchers Alasdair Allan and Peter Warden in April revealed that a previous iPhone operating system recorded the longitude and latitude of its owners' movements and saved the information, which could then be read by anyone with access to the phone.
"We have also examined the system following the study of the British researchers," said Yann Padova, who heads France's CNIL, the government's techonology consumer protection body.
"We have sent two letters to Apple, who have responded to us in part. We received some clarifications, but they were not complete. The file is still under investigation," Padova added.
He however assured that on the basis of information provided by Apple, it appeared "the data collected was stored in the handset and was not transmitted to back Apple or its commercial partners," Padova said.
"Apple has worked on improving the information," provided to its clients about the existence of this stored data, he added.
But Padova said key technical questions remain unanswered, notably how Apple secures the data collected on its mobile devices.
Earlier Wednesday, the Korea Communications Commission (KCC) said it would fine Apple Korea up to three million won ($2,829) over the tracking issue.
It also criticised but did not punish search giant Google for its role in collecting the data.
Apple Korea spokesman Steve Park said his company did not collect the location data of iPhone users.
"Apple is not tracking the location of your iPhone. Apple has never done so and has no plan to ever do so," he told AFP, declining to say whether the company would agree to pay the fine.
Apple in May released updated software for iPhones to fix "bugs" that resulted in location data being unencrypted and stored for up to a year.
France's CNIL said it could still impose fines on the company if it finds evidence of wrongdoing.