His trip came during a busy time for the US Department of Justice, under which the FBI is the main investigative agency.
The US Department of State issued a shelter-in-place warning on Sunday for American citizens in parts of Mexico because of unrest after local authorities killed a drug cartel leader.
The FBI is also helping in the search for Nancy Guthrie, the mother of NBC News anchor Savannah Guthrie, who has been missing for more than three weeks.
Public flight data showed Patel took a government plane last Thursday from Joint Base Andrews near Washington DC to a US Air Force base in Italy.
The FBI last week denied Patel was on a personal trip, saying it was planned months ago.
The agency said it had a major role in Olympic security and that Patel was meeting Italian law enforcement officials and the US ambassador to Italy.
Congressman Jason Crow, a Colorado Democrat, described Patel’s Olympic trip as “grift and corruption”.
“Your taxpayer dollars funding the FBI director’s Italian vacation,” he posted on X.
Xochitl Hinojosa, a former justice department spokeswoman under President Biden, posted on X that “our FBI Director thinks he’s a frat bro”.
Patel himself has previously come under scrutiny for his use of FBI jets.
Last November, he reportedly used the FBI’s plane to fly to Pennsylvania and see his country music star girlfriend Alexis Wilkins perform.
Congressional Democrats said in December they were investigating reports that Patel flew on an FBI jet to a hunting resort in Texas and a golfing trip in Scotland.
Patel once criticised his predecessor as FBI Director, Christopher Wray, for using the agency’s jet for personal travel.
FBI directors are banned from flying commercially for security reasons, but must reimburse the government for personal use of the plane at the price of an airline ticket.
