The U.S. Air Force has lodged crews at President Donald Trump’s Scotland resort—Trump Turnberry—up to 40 times since 2015, Politico reports. The number, from the preliminary results of an Air Force review, does not indicate how many of those trips occurred after Trump became president. The number also does not indicate how many people stayed at Turnberry on each of the trips—though crews between five and almost 40 people have stayed at the resort in at least four stays since September 2018.

The Air Force reportedly ramped up its overnight stops in Scotland after signing a contract with Prestwick Airport, more than 20 miles from Turnberry, in the final months of the Obama administration. The Air Force said the refueling stops at Prestwick are within Pentagon guidelines, but a Monday memo said that an internal review would be launched to look into “guidance associated with the use of civil airports and lodging selection for aircrew at en route locations.” The House Oversight Committee has also been probing Turnberry-related U.S. military expenditures for the last few months over conflict-of-interest concerns. In a Monday tweet, Trump declared the overnight stays had “nothing to do” with him.