Online review service Yelp Inc. has recently joined a European Union(EU) antitrust case against Google, accusing the Internet search giant of siphoning clicks away from Yelp in favor of Google+ social network.

Joining the EU case against Google, Yelp has submitted a study which apparently shows that algorithms are being deliberately tampered by Google in an attempt to ensure that Google+ preferentially ranks higher than Yelp. Yelp has alleged that the preferential positioning of Google+ over Yelp comes to the fore even when users specifically search for Yelp reviews.

According to the allegations leveled by Yelp, the study - for which random people were recruited online - has revealed that a search for Yelp reviews of certain restaurants/ lounges or other businesses turns up a link to the official site of the businesses, along with a link to their Google+ page.

Yelp said that though the results seemingly do not have any negative impact Yelp's overall traffic, it still becomes evident that Google "appears to be intentionally serving up search results that contradict the users' intent in order to preference Google+."

Meanwhile, though it is not certain whether Yelp's complaint will be rejected or accepted as part of the antitrust proceedings against Google, EU will still have to "formally respond" to Yelp on the matter. Moreover, the complaint will also give Yelp certain rights to appeal if EU works out a settlement with Google.