Chilean officials have accused the World Bank of treating the country unfairly for several years.
Foreign Minister Heraldo Muñoz, tweeted "fake news was becoming fake statistics".
He was responding to an interview given by the bank's chief economist, Paul Romer, who said indicators for Chile may have been manipulated for political reasons to show a decline in Chile's business conditions.
The World Bank has ordered an enquiry.
In an interview given to the Chilean newspaper El Mercurio, the World Bank economist who had been responsible for the rankings, Augusto Lopez-Claros, said changes in methodology "took place in a transparent and open context," denying any political bias.
Chile currently ranks 55th out of 190 countries on the World Bank's closely watched annual "Doing Business" competitiveness rankings.
It had been 34th in 2014, the year socialist President Michelle Bachelet took office.
"What happened with the World Bank's competitiveness rankings is very concerning, "said President Bachelet, whose four-year term ends in March.
"Rankings that international institutions conduct should be trustworthy, since they impact on investment and a country's development." she said, asking for a formal investigation.
Mr Muñoz called on Twitter for the bank to "calculate the possible loss in foreign investment because of the doubts caused by a lower competitiveness ranking during the administration of President Bachelet".
Chile's presidential elections last month were won by the conservative business tycoon, Sebastián Piñera against Ms Bachelet's preferred candidate, Alejandro Guillier, in part on promises to slash red tape and boost investment.
The World Bank's "Doing Business" rankings weigh factors such as the ease of starting a business, obtaining credit, paying taxes and getting construction permits.