Health and Human Services Secretary Tom Price speaks Sept. 15 at an event in Pennsylvania, where he reportedly traveled by private chartered jet. (Jacqueline Larma/AP)

The Health and Human Services inspector general is investigating Secretary Tom Price’s reported use of chartered planes for at least two dozen flights in recent months at taxpayer expense, a spokeswoman said Friday.

Investigators will seek records of Price’s travel and review the justifications that he and his staff gave for the trips, the spokeswoman for HHS Inspector General Daniel R. Levinson said.

House Democrats wrote to Levinson, an appointee of President George W. Bush, on Wednesday requesting the investigation. They said the flights appeared to violate federal law designed to make sure executive branch officials use the most economical travel available.

Democrats cited a Politico report that Price last week took five private charter flights along routes and at times when commercial flights were available for a fraction of the cost. In a second story, the news organization reported that the Georgia Republican has taken at least 24 such flights since early May. The flights cost taxpayers a reported $300,000.

“The review focuses on whether the travel complied with federal travel regulations but may encompass other issues related to the travel,” said Tesia D. Williams, the spokeswoman. “We take this matter very seriously, and when questions arose about potentially inappropriate travel, we immediately began assessing the issue. I can confirm that work is underway and will be completed as soon as possible.”

Also Friday, the Treasury Department’s Office of Inspector General said it is investigating two instances when Treasury Secretary Steven Mnuchin used government planes for travel. Last month, Mnuchin and his wife, Louise Linton, flew to Louisville, Ky., on a government jet to attend a luncheon and visit the nation’s gold vault at Fort Knox, where Mnuchin also viewed the solar eclipse. Days later, Mnuchin flew on a government jet from New York City to Washington following a news conference with President Trump at Trump Tower.

Price’s office this week sought to justify his use of chartered jets, saying the secretary’s office evaluates the most effective way for him to travel and finds that it is sometimes necessary to charter planes to allow Price to both manage one of the largest executive branch agencies and stay grounded with voters.

“This is Secretary Price, getting outside of D.C., making sure he is connected with the real American people,” said Charmaine Yoest, his assistant secretary for public affairs.

Yoest said that early in his tenure in the Trump administration, Price was delayed at an airport and forced to cancel a public event. “Wasting four hours in an airport and having the secretary cancel his event is not a good use of taxpayer money,” Yoest said.

Democrats have blasted Price’s use of private jets — some with plush leather chairs, kitchens and other amenities — as hypocritical at a time when he has sought deep budget cuts at the National Institutes of Health and a repeal of President Barack Obama’s Affordable Care Act.

On one flight last week, Price traveled to New Hampshire, his staff acknowledged. In a statement Thursday night, Sen. Margaret Wood Hassan (D-N.H.) criticized him for doing so.

“The Trump Administration’s use of taxpayer-funded private planes keeps getting worse — all the while they continue trying to rip health care insurance away from millions and drive up costs for hard-working Granite Staters and Americans,” Hassan said.

On Friday, the top Democrat on the House Oversight and Government Reform Committee called on House Republicans to hold a hearing on Price’s travel and asked Price for details on the number of noncommercial flights that he or other agency officials took, how much they cost and any documents justifying the private-jet travel.

“If these recent reports are accurate, this would be a stunning and hypocritical breach of trust, given that the Trump Administration at the same time is trying to take away healthcare from millions of Americans and is proposing to slash funding at HHS — negatively affecting critical programs to provide early-childhood education, fund Medicare for seniors, and conduct medical research and development,” wrote Rep. Elijah E. Cummings (D-Md.) in his letter to HHS.

“The amount of taxpayer funds you reportedly spent on just one single flight earlier this month is more than some of my constituents make in an entire year,” Cummings continued.

There is precedent for a ­Republican-controlled House to hold a Republican president’s administration accountable for lavish travel expenses. During Bush’s tenure, the House oversight committee obtained travel records from 10 agencies and found that several Cabinet members took private charter flights to meetings, conferences and other events.

Then-HHS Secretary Michael Leavitt used private charter travel the most, taking a jet leased by the Centers for Disease Control and Prevention to visit some 90 cities at a cost of more than $700,000.

A small number of Cabinet members, military officials and law enforcement officials are allowed to travel on government planes for national security reasons. For other federal officials, however, strict travel regulations require agencies to cite exceptional circumstances to justify using noncommercial flights.

A frequent justification used by executive branch officials is a lack of comparable options to accommodate the schedule for a trip. Politico, however, identified several commercial flight options with departure and arrival times comparable to those of the five chartered flights it said Price took last week.

Yoest said Price’s schedule was especially fluid last week. Before one chartered flight from Washington to Philadelphia, for instance, he had to attend a hurricane briefing.

Meanwhile, the New Hampshire appearance, she said, was to present $144 million in grant funding for services to combat opioid addiction.

Discussions about the costs of the flights are “grossly underestimating the point that this is official business,” Yoest said.

Travel policies for the Department of Health and Human Services, last updated during Obama’s second term, require the assistant secretary for administration and a senior agency travel official to approve noncommercial flight plans.

Jack Gillum and Drew Harwell contributed to this report.