Google's formula for recommending websites in the US is being questioned in a lawsuit that alleges its search is biased.

A Texas attorney general is leading the investigation which is said to be looking at whether or not Google manipulates its search results to stifle competition.

How high Google ranks a website following a search query can literally make or break it, due the sheer volume of traffic Google passes on.

A website that continually ranks at the top of the first page of search results will most likely get large amounts of traffic and therefore be able to generate more revenue from ads or sales.

The opposite can be said for some websites that rank low on search results.

In a blog post, Google said, “We look forward to answering questions because we're confident that Google operates in the best interests of our users.

"Given that not every website can be at the top of the results, or even appear on the first page of our results, it's unsurprising that some less relevant, lower quality websites will be unhappy with their ranking."