People who own Android mobile phones are being warned about the consequences of downloading certain apps.

It comes as consumers are being told to check their devices and delete apps that could be draining battery life and using up mobile data even when the screen is switched off, reports The Mirror.

This problem has been discovered by the security team at McAfee with the tech specialists finding a total of 43 apps that were running adverts when a device wasn't in use.

This method is banned by Google as it is a “clear violation” of the Google Play Developer policy.

By some designing apps to do this, it’s a forbidden way to get to make money and generate advert clicks without the permission of users.

Many of the applications that were available on the Play Store have since been taken down by Google, but not before around 2.5 million people had installed them onto their devices, explains The Mirror.

What Android apps are affected by this and how does it work?

McAfee has reported just some of targeted apps are TV/DMB Player, Music Downloader, News, and Calendar applications.

To avoid detection, the produced adverts only begin to pop up a few weeks after they are first installed.

This means it is harder to spot the scam as it doesn’t appear straight away.

McAfee is now urging people to check what permissions the software of each wants before downloading them.

You should also keep an eye on the battery life and if it suddenly starts to fall, there could be means for something suspicious happening in the background.

McAfee said: "It is essential for users to exercise caution and carefully evaluate the necessity of granting permissions like power saving exclusion, or draw over other apps before allowing them.

“While these permissions might be required for certain legitimate functionalities for running in the background, it is important to consider the potential risks linked with them, such as enabling hidden behaviours or reducing the relevance of ads and contents displayed to users because the hidden Clicker behaviour."

The Mirror adds: "It's thought the majority of users affected by this latest advert attack were based outside of the UK and USA but that doesn't mean your phone can't be affected in the future."