The Information Commissioner's Office is making enquiries with Google over its actions around Internet Explorer (IE) privacy policies.
The investigation has been spurred by a dispute that erupted this week between Google and Microsoft over how the search engine monitors users' online behaviour.
Microsoft has accused Google of using third party cookies to track user behaviour online, when Microsoft has put in place default settings to circumvent this from happening in IE.
IE typically blocks third party cookies unless a website presents a P3P Compact Policy Statement indicating how the site will use the cookie, where it states that the site's use does not include tracking the user's behaviour. However, Microsoft claims Google's P3P policy causes IE to accept Google's cookies even though it does not state how Google intends to use them.
Google has responded to Microsoft's criticisms by insisting that it is well known that it is "impractical to comply with Microsoft's request while providing modern web functionality".
An ICO spokesperson has confirmed that it is making "ongoing enquiries" with Google over Microsoft's claims in order to ensure that Google is complying with both the Data Protection act and EU Privacy and Communications Regulations.
The ICO could not confirm when these enquiries would be completed, or what the outcome of the investigation might be.
This is not the first time Google has come under the ICO's spotlight, as in 2010 it was found to have broken the law by collecting data via unencrypted Wi-Fi networks when it was collecting images for its Street View service. However, the ICO did not fine Google over the breach and instead demanded that it undergo an audit of its privacy policies.