(CNN) The State Department spent at least $233,732 on President Donald Trump's July 2018 trip to his Turnberry resort in Scotland, according to a letter from the department's inspector general obtained by CNN.

The July 22 letter from Inspector General Steve Linick to Democratic Sens. Tom Carper of Delaware and Elizabeth Warren of Massachusetts and Rep. Elijah Cummings of Maryland details only the costs that were paid by the State Department and not reimbursed. Among the costs were more than $42,000 in overtime, more than $111,000 in hotels, more than $28,000 in rental cars and more than $51,000 in temporary duty costs, according to the letter.

The OIG review was not able to determine how much the resort gained in profit from the visit. The State Department spent $728 on three rooms for two nights at the Trump-owned property. According to the letter, the department said they were used by the US ambassador to the United Kingdom, his wife and his chief of protocol. The department said that the Trump Turnberry's rate was "the lowest of all the hotels being utilized for this VIP visit" and offered "a fair and reasonable rate to the Government," according to document cited in the letter.

The Hill was the first to report on Linick's letter.

The State Department OIG review was prompted by a call for investigation made by the three Democratic lawmakers shortly after the President's trip. They also requested an inquiry from the Department of Homeland Security's Office of Inspector General. The department OIG did not immediately respond to CNN's request for comment Monday.

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