BARI, Italy (Reuters) - An Italian prosecutor is investigating Deutsche Bank DBKGn.DE over its sale of 7 billion euros ($8 billion) of Italian government bonds five years ago, an investigative source told Reuters.

A statue is seen next to the logo of Germany's Deutsche Bank in Frankfurt, Germany, January 26, 2016. REUTERS/Kai Pfaffenbach/File Photo

A prosecutor in Trani, a town in southern Italy, is investigating because Deutsche Bank allegedly told clients in a research note in early 2011 that Italy’s public debt was no cause for concern, and then sold almost 90 percent of its own holding of the country’s bonds, the source said on Friday.

“We do not believe there is a case to answer here and are confident that we acted appropriately,” a spokesman for Deutsche Bank said in an email to Reuters, adding the German lender was cooperating with Italian authorities.

Deutsche Bank sold the bonds in the first half of 2011 as Italy slid toward a debt crisis that eventually brought down the government of former Prime Minister Silvio Berlusconi.

Italy’s economy ministry said in August 2011 that Deutsche Bank had explained the sale by saying it needed to balance out its exposure to Italian debt after taking on more when it bought out Deutsche Postbank in 2010.

Five former Deutsche Bank managers as well as the bank itself are under investigation in Trani, the source added.

The same prosecutor has, in recent years, also opened investigations into ratings agencies Moody’s, Standard & Poor’s and Fitch, saying their reports on Italy and its banks during the crisis were mismanaged and provoked sharp losses on the Milan stock market.

The case against Moody’s was dropped before a trial began in Trani last year. The case against Fitch Italia and its country head was moved to Milan, where a judge threw it out on Friday.

However David Riley, Fitch’s former head of sovereign ratings, remains on trial in Trani, along with five S&P officials. The ratings agencies have denied wrongdoing.

The U.S. ambassador to Italy, John Phillips, mentioned the ratings agency probe in a speech in Milan last month in which he said Italy’s justice system was deterring investors.

In the United States it was “highly unlikely that such a case would be brought outside the major financial centers, where prosecutors have both jurisdiction and expertise in securities fraud prosecutions,” Phillips said.