The Bush administration was forced yesterday to issue a grovelling apology to the Italian prime minister, Silvio Berlusconi, after White House officials briefed the travelling US press corps that Berlusconi was regarded as a political amateur who had used his massive media influence to gain political power.

The briefing given to White House press corps was lifted, administration officials said, from the Encyclopedia of World Biography, and put in a briefing pack as though it represented the views of the administration.

Berlusconi has prided himself on being Bush's natural ally in Europe. But the profile described him as "one of the most controversial leaders in the history of a country known for governmental corruption and vice ... regarded by many as a political dilettante who gained his high office only through use of his considerable influence on the national media until he was forced out of office in 2006."

White House spokesman Tony Fratto said the biography used "insulting" language and "the sentiments expressed in the biography do not represent the views of President Bush, the American government, or the American people. We apologise to Italy and to the prime minister for this very unfortunate mistake," he wrote in a letter distributed via email.

When asked about the biography, Berlusconi said that he wasn't the one who had sought an apology, suggesting the Italian media had generated the controversy. Italy "is a country that loves to flagellate itself and make itself look bad", he said.