US authorities have been investigating Oracle for at least a year to see if the business software titan violated anti-bribery laws in its overseas business, the Wall Street Journal reported Wednesday.

Citing unnamed sources, the Journal said the Federal Bureau of Investigation (FBI) and the Justice Department have been pressing a criminal investigation, as the Securities and Exchange Commission looks into possible civil violations.

It cited one of the sources as saying that part of the wide-ranging investigation was focused on Oracle's sales to government agencies in Western and Central African countries.

A 1977 law makes it illegal for certain individuals or companies to make payments to foreign government officials in return for assistance in gaining or retaining business.