Investigators probing how sensitive information such as income figures was leaked to a news outlets have made referrals to the FBI, a tax official said this week. “Treasury announced yesterday that they made investigative referrals to their Office of Inspector General as well as the FBI, and the United States Attorney’s Office for the District of Columbia,” Douglas O’Donnell, a deputy commissioner at the Internal Revenue Service (IRS), told a congressional committee in Washington on Thursday. “We fully support any investigation under taken and will urge the investigative authorities to keep Congress appropriately informed of their findings.” IRS officials “want to know what happened, urgently,” he added. “We take this matter very seriously. And we’ll be pushing as hard as we can to ensure that we learn as soon as possible, what actually did happen.” ProPublica published files that some of the wealthiest Americans, including Amazon founder Jeff Bezos and …