Apple's newly-released operating system for Macs, OS X Yosemite, sends search terms from the 'Spotlight' feature, coupled with data about the computer's location, to Apple and other third parties, including Microsoft.
Researchers have discovered that - alongside searching files, folders and installed applications on the machine for the entered keyword - the feature is configured to send location and search data back to Apple and other companies in order to return searches from the App Store and Microsoft's Bing search engine for relevant information or websites.
The transmission of search and location data is enabled by default in OS X Yosemite and is noted in Apple's terms of service.
“When you use Spotlight, your search queries, the Spotlight Suggestions you select, and related usage data will be sent to Apple,” the company’s “About Spotlight Suggestions” document states.
“If you have Location Services on your device turned on, when you make a search query to Spotlight the location of your device at that time will be sent to Apple.”
The feature can be switched off - users can disable 'Spotlight Suggestions' and 'Bing Web Searches' by choosing 'system preferences' from the Apple menu, and choosing 'search results' from the 'spotlight' option.
The collection of search and location data also appears in Apple's new iOS 8 operating system.
The feature is not switched on by default in all regions, but Australia appears as one country in which Spotlight Suggestions are automatically enabled, according to Apple's iOS 8 features list.
"Searches for common words and phrases will be forwarded from Apple to Microsoft's Bing search engine," the iOS 8 Spotlight terms state.
"Location, search queries and usage information sent to Apple will be used by Apple only to make Spotlight suggestions more relevant and to improve other Apple products and services."
Spotlight Suggestions can also be turned off in iOS 8 by selecting the 'off' option for 'Spotlight Suggestions' and 'Bing Web Results' within general settings. Location services can also be switched off for Spotlight Suggestions within the privacy settings.
The feature is also included in Apple's Safari web browser, and is similarly enabled by default. It can be turned off by unchecking '"Include Spotlight Suggestions' in the 'Search' option within Safari 'Preferences'.
The types of data transmitted in the Spotlight Suggestions search specifically includes approximate location, device type, client app, device language settings and the previous three apps used by the device owner, according to the most recent iOS security report.
The information is grouped into one session ID which resets every 15 minutes, and is transmitted over an HTTPS connection.
Spotlight Suggestions was highlighted by a new project aimed at identifying the data collected by Apple and third parties, fix-macosx.com.
"A myriad system and user processes are sending data to Apple in a default configuration, and we want to fix those, too," the website states. "This work is powered by Net-Monitor, our open-source toolkit for auditing phone home behaviour system-wide.
The site, reportedly run by software developer Landon Fuller, states that while the data collection is only intended to improve the quality of searches conducted through Spotlight, "Mac OS X has always respected user privacy by default, and Mac OS X Yosemite should too".
The publicity comes at a bad time for Apple, which is increasingly attempting to portray itself as privacy-focused in an environment of national security surveillance concerns.
Apple recently announced it would attempt to block law enforcement requests for user data in iOS 8 by effectively locking itself out of devices.
It claimed to have built a technical barrier in the new mobile operating system to remove its ability to hand over user data to government agencies - a move quickly followed by Google with its Android 5.0 Lollipop mobile operating system.