Google could be slammed with a fine of at least $5 billion in a US lawsuit if found to have illegally gathered data from millions of users surfing the internet privately through its Chrome browser, Reuters reported.

A complaint filed in a district court yesterday (2 June) accused the tech giant of secretly collecting information about people’s search habits despite using the web browser’s Incognito mode.

Complainants argue data was gathered by Google Analytics, Google Ad Manager and smartphone apps, regardless of whether users clicked on adverts or not. The plaintiffs claimed millions of users employing Incognito mode since 1 June 2016 were affected and sought damages of at least $5,000 per person.

Google representative Jose Castaneda told Reuters the company will vigorously defend itself against the allegations, adding it clearly highlighted websites could be able to collect information about browsing activity conducted in private mode.

The Alphabet-owned company has long faced claims regarding unauthorised tracking, most recently being accused by authorities in Arizona of breaking state law by continuing to gather information from devices where the Location History feature had been deactivated.