In a news release Tuesday, the Tennessee Republican said he had just been informed by the Senate legal counsel's office that law enforcement agents were conducting a search of Ryan Loskarn's home. Loskarn is the chief of staff in Alexander's Washington, D.C., office.
"I am stunned, surprised and disappointed by what I have learned," Alexander said in the news release.
Phone and email messages left for Loskarn were not immediately returned.
Alexander said that he immediately placed Loskarn on administrative leave without pay and that his office is fully cooperating with the investigation.
Alexander is a former Tennessee governor and has also served as the U.S. Secretary of Education. He was first elected to the Senate in 2002.
According to Loskarn's biography on his LinkedIn account and several editions of "Who's Who," Loskarn graduated from Tulane University in 2000 and went to work for retired Republican U.S. Rep. Wally Herger of California as a legal assistant.
Loskarn went on to work as the communications director for U.S. Rep. Marsha Blackburn, a Tennessee Republican, and eventually became staff director for the Senate Republican Conference.
Loskarn has served as Alexander's chief of staff for two years.