Angela Dorothea Merkel is a German stateswoman and former research scientist. Merkel has been the Chancellor of Germany since 2005, and the leader of the Christian Democratic Union since 2000. She said that the way search engines and social networks like Google and Facebook choose what people see online should be made public.

"The algorithms must be made public so that one can inform oneself as an interested citizen on questions like what influences my behavior on the internet and that of others?" Merkel said, RT reported.

"This is a development that we need to pay careful attention to," Ms Merkel said in a keynote speech to the Medientage conference in Munich earlier this week.

"The big internet platforms, via their algorithms, have become an eye of a needle, which diverse media must pass through to reach users," she added.

"These algorithms, when they are not transparent, can lead to a distortion of our perception, they narrow our breadth of information," she warned.

Mrs Merkel called on the algorithms to be made public so "informed citizens" can see the influences on what they are fed via social media, news feeds and search results.

According to Merkel, the information was drawn from a limited list of sources in many cases and situations.

"What we have right now is an incredibly influential platform that has no reason to measure its influence because it will likely open it up to regulation," she said.

Thomas Jarzombek, the digital policy spokesperson of Merkel's Christian Democratic Union, told Spiegel Online he did not think she was suggesting companies such as Google and Facebook should reveal their trade secrets.

"But we do need more information from these operators as to how their algorithms function generally speaking," he added.

According to BBC, a cross-party group of German politicians will send the results of an investigation into algorithms used by Facebook, Google and other internet firms to the EU's digital commissioner Gunther Oettinger. This will be expected in late 2016.