Treasury Secretary Steven Mnuchin sought to use a U.S. Air Force jet for his honeymoon to Europe last month for national security reasons, a request that was later withdrawn.

Mnuchin and his wife, actress Louise Linton, eventually decided not to travel on a government plane, the Treasury Department said in a statement after an ABC News report on the matter. His request is now part of an inquiry by the Treasury Department’s Office of Inspector General, ABC news reported Wednesday, citing unnamed officials. The cost is about $25,000 per hour, ABC reported, citing an Air Force spokesman.

Mnuchin’s request for personal travel at taxpayer expense was made out of concern for him having a secure method of communications, given issues ranging from Iran to Venezuela to North Korea, a Treasury spokeswoman said. After it became apparent that other methods of protected communication were available, Mnuchin decided not to use military aircraft, she said.

Treasury secretaries in the past two decades have typically traveled on commercial airlines for domestic travel and have occasionally taken government aircraft on overseas trips to help facilitate their schedules or to account for security precautions.

The inquiry was initiated after Mnuchin, a former Goldman Sachs banker and Hollywood producer, and Linton traveled Aug. 21 to Louisville, Kentucky, where he discussed tax policy at a public event and then toured Fort Knox. The Treasury inspector general said it is reviewing the trip “to determine whether all applicable travel, ethics and appropriate laws and policies were observed” in response to public inquiries.

Rich Delmar, counsel to the inspector general, said by telephone Wednesday that the review is now looking at “all requests for and use of government aircraft” by Mnuchin.

The Treasury said that Linton, 36, will reimburse the government for transportation costs when she travels with Mnuchin on official business. Inquiries into her travel with Mnuchin were triggered after she drew attention to her trip to Kentucky in an Instagram post. Linton responded condescendingly to a critic, where she had posted a photo of herself exiting a U.S. government plane, holding a handbag that sells for more than $10,000.

On social media, Linton, responding to an Oregon woman who criticized her “little getaway” to Kentucky, wrote “I’m pretty sure we paid more taxes toward our day trip than you did.” The actress also said she’s “pretty sure the amount we sacrifice per year is a lot more than you’d be willing to sacrifice if the choice was yours,” adding, “you’re adorably out of touch.”

Linton later apologized, and while posing for the cover of Washingtonian magazine wearing a ballgown, acknowledged her Instagram post as “indefensible.”

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