Google's latest update to its search engine algorithm, named Panda, rolled out 11 April in order to weed out content farms - websites that take content from other sites to get more hits. However, this has led to accusations Panda also has downgraded the rankings of other, more legitimate sites.
In an official blog post, Google stated the purpose of the update: "This update is designed to reduce rankings for low-quality sites - sites which are low-value add for users, copy content from other websites or sites that are just not very useful."
"At the same time, it will provide better rankings for high-quality sites - sites with original content and information such as research, in-depth reports, thoughtful analysis and so on."
Yet some websites have had their rankings marked down in what they consider an unfair way, including Ciao.co.uk, a shopping and price comparison website owned by Microsoft and leading an EU competition case against Google.
According to the Searchmetrics, Ciao's ranking in Google fell by 94 per cent. A similar review by Sistrex showed an 81 per cent drop for the site.
Microsoft then claimed Google used their dominant position in the search engine market to limit the rankings of their rival's products, in this case, the Redmond-owned Ciao.co.uk
Google's Scott Huffman, when interviewed by the AFP news agency, denied his company had done anything wrong: "If you think of the scale of what we are talking about, it is almost absurd to say we could rig results."