Google has reportedly been collecting user location data from phones running its Android software even when the device's location services have been turned off. The company has been collecting such data on Android users since the beginning of 2017.

According to an investigation by Quartz, the publication observed Android phones have been collecting the addresses of nearby cellular towers and sending the encrypted data back to Google, allowing the company to roughly track the locations and movements of users with these phones. This happens when the phone is connected to a Wi-Fi network, even if location services have been disabled.

Details were still collected even if a device has been reset to factory default settings, no mobile apps have been installed and there is no SIM card installed in the phone, as long as the phone is connected to the internet. The publication noted that there is currently no way for users to opt-out of this practice.

A Google spokesperson told Quartz that cell tower addresses have been included in information sent to the system Google uses to manage push notification and messages on Android phones over the past 11 months. However, the data collected was never used or stored, the spokesperson said.

"In January of this year, we began looking into using Cell ID codes as an additional signal to further improve the speed and performance of message delivery," the Google spokesperson said in a statement. "However, we never incorporated Cell ID into our network sync system, so that data was immediately discarded, and we updated it to no longer request Cell ID."

The company is currently taking steps to end the practice by the end of November. It is not immediately clear how cell tower addresses would help Google improve its message delivery service.

A source familiar with the matter told Quartz that the cell tower addresses were sent to Google following a change earlier this year to the Firebase Cloud Messaging service owned by Google that runs by default on Android phones.

According to Google's terms of service: "When you use When you use Google services, we may collect and process information about your actual location. We use various technologies to determine location, including IP address, GPS, and other sensors that may, for example, provide Google with information on nearby devices, Wi-Fi access points and cell towers."

However, it does not specify if this is applicable when a user actively switches off location services.

Given that many apps do not function properly unless location services is turned on, it is not surprising that Google keeps track of your phone's location. Still, the revelation does raise serious concerns over users' digital privacy and security.

Google and other tech giants including Facebook have come under fire from regulators and lawmakers in numerous countries, particularly in Europe, regarding their data collection practices and the massive amount of sensitive data it gathers regarding a person's life, habits and preferences.