Some hours earlier, Google had said it would not allow fake news websites to use its advertising software.

The move comes after both companies were criticised for assisting misinformation campaigns.

Facebook, in particular, has been accused of allowing fake news stories to spread across its social network. Critics have claimed that widely-shared articles, including one claiming the Pope had endorsed Donald Trump and another that Hillary Clinton’s house had been raided by the FBI, helped Donald Trump win support in his run to the White House.

Google was dragged into the row over the weekend when a search for “final election results” prominently displayed a news story from a website called 70news falsely claiming that Mr Trump had won more votes that Ms Clinton.