Google shares data harvested from most apps, according to a new comprehensive study of apps used by Android devices.

A research team from Oxford University analysed 959,000 Android apps available in Google Play stores in the UK and the US and found that 90% of them shared data with Google. The researchers also found that about 50% of the apps shared data with a minimum of ten other third parties, including Twitter and Facebook.

The authors of the study said that the increase in the number of “freemium” apps that derived their revenue from data sharing and advertising was responsible for the harvesting and sharing of data with Google and other companies.

The information that the apps collected and shared included the gender, age and location of the person using the app. The study found that apps geared towards children and news apps were the worst offenders and noted that the data harvesting and sharing practices present challenges to both companies responsible for complying with privacy laws and the regulators who enforce these laws.

Industry executives were not surprised by the study’s findings, as so many technology companies now use a business model that monetises the collection of data.

Frederike Kaltheuner from Privacy International said that it is “impossible” for the average app user to understand how companies are using their data and how to opt out.

Data collection is no longer about trying to determine which ads are the most relevant to display but about maximising profits at the expense of the right to privacy, she added.