New documents provided to the House Oversight Committee show the Department of Defense spent at least $184,000 at President Trump's Turnberry golf resort in Scotland over the course of two years. The committee sent its third letter to the Pentagon Wednesday demanding more documents about taxpayer funds spent at the property, which is about 50 miles outside of Glasgow.

Democratic Chairman Elijah Cummings and Congressman Jamie Raskin said the Pentagon had provided only 21 pages of documents in response to committee requests.

"The Department failed to produce any underlying invoices or travel records relating to spending at Trump Turnberry or Prestwick Airport. It is unclear why the Department has taken so long to produce such rudimentary and deficient information," the two wrote, referring to the struggling airport near the resort that has been the focus of scrutiny in recent weeks.

Get Breaking News Delivered to Your Inbox

Cummings and Raskin wrote that, according to data provided by the Pentagon, "taxpayer funds have been used to pay for more than three dozen separate stays involving hundreds of nights of rooms-all after the President was sworn into office." The department told the committee average cost was $189 per night, and that between August 2017 and July 2019, expenditures "specifically associated with the Trump Turnberry ... amounted to $124,578.96."

An additional $59,729.12 in unspecified charges was billed to government travel cards, raising the total spending at Turnberry to more than $184,000.

A general view of the Trump Turnberry hotel and golf resort in Turnberry, Scotland, on June 24, 2016. Oli Scarff / AFP/Getty Images

"If both of these claims are accurate, it appears that U.S. taxpayer funds were used to purchase the equivalent of more than 650 rooms at the Trump Turnberry just since August 2017 — or the equivalent of one room every night for more than one-and-a-half years," the lawmakers wrote in their letter.

The Oversight Committee is also investigating increased activity by the U.S. military at the struggling Prestwick Airport, which is a key access point for Mr. Trump's Turnberry resort. Lawmakers sent a letter to the Department of Defense earlier this month requesting information on military spending at that airport. This investigation into the airport was first reported by Politico.

Mr. Trump purchased and renovated the resort for hundreds of millions of dollars two years before the 2016 election. In a letter to the Department of Defense, the committee said the airport also offers discounted rooms and free rounds at the Turnberry golf course to visiting military and civilian crews.

"Given the president's continued financial stake in his Scottish golf courses, these reports raise questions about the President's potential receipts of U.S. or foreign government emoluments in violation of the U.S. Constitution and raise other serious conflict of interest concerns," the letter to the Defense Department said. The Scottish government was considering selling the airport before the 2016 election.

The committee asked for documents showing communications between the Department of Defense and both the airport and golf course.

"We have been investigating this incident and other similar reports," a senior Democratic committee aide told CBS News. "The Defense Department has not produced a single document in this investigation. The committee will be forced to consider alternative steps if the Pentagon does not begin complying voluntarily in the coming days."