The HHS inspector general's office began a review last week to determine if Price complied with federal travel regulations, which generally require officials to minimize costs.
On Wednesday, the House Committee on Oversight and Government Reform released a letter asking Price for details on his use of "government-owned aircraft for personal travel or private non-commercial aircraft for official travel". The committee wants details by October 10.
The letter reminded Price and other recipients that official travel for all federal employees must be "by the most expeditious means of transportation practicable", and be in line with an employee's function.
During a wild and widely panned speech at the Boy Scout Jamboree in July, President Donald Trump famously threatened, tongue in cheek, to fire Tom Price if he did not help get Obamacare repealed and replaced.
Responding to questions from reporters, Trump said he is "looking into" the situation and "personally, I'm not happy about it, and I let him know it".
Trump tax plan expected to double standard deduction, lower corporate rate
But numerous specifics, such as whether the individual tax cuts would favor the wealthy, are still to be worked out. However, the president still believes that it is possible to decrease corporate taxes to a low of 15 percent.
On a June trip to Nashville, Price also had lunch with his son, who lives in that city, according to Politico.
HHS contracted the flight to Georgia to take Price to five states within four days, according to the article, costing more than $86,000. Commercial flights departing and arriving at around the same time would have cost in the ballpark of $300.
Lawmakers are demanding information on political appointees' use of government planes for personal travel, as well as their use of private charters for official travel.
Price said he would suspend his use of private planes while the OIG conducted its investigation.
Earlier Wednesday, a top White House official said the administration was awaiting the internal and congressional inquiry into Price's use of private jets but declined to say whether the President had confidence in the secretary. 5 big ideas to halt America's opioid epidemic Aligning clinical and community resources improves health MORE said Tuesday that her successor's use of private chartered flights is "stunning".