Washington (CNN) The Air Force has ordered a review of all international layover stays following controversial visits by crew members at Donald Trump's Turnberry resort during refueling stops, which have again raised ethics questions about government use of the President's private entities.

"Air Force leadership directed Air Mobility Command to review all guidance pertaining to selection of airports and lodging accommodations during international travels," the Air Force said in a statement Sunday evening, which was first reported by Politico.

The House Oversight and Reform Committee earlier this year launched a probe of the stays after aircraft would be directed to land at Prestwick Airport, in Glasgow, Scotland. The crew members would then stay at Turnberry. The Air Force had previously launched a separate inquiry into those stays.

Over the weekend, it was reported that a US Air Force C-17 crew stayed at the Turnberry resort during a March refueling stop en route to Kuwait, another example of Trump's company earning money from taxpayer dollars, which has led some government watchdogs to argue the arrangements breach ethical norms and potentially violate a clause of the US Constitution.

"While initial reviews indicate that aircrew transiting through Scotland adhered to all guidance and procedures, we understand that U.S. Service members lodging at higher-end accommodations, even if within government rates, might be allowable but not advisable," the Air Force said in its statement Sunday evening. "Even when USAF aircrews follow all directives and guidance, we must still be considerate of perceptions of not being good stewards of taxpayer funds that might be created through the appearance of aircrews staying at such locations."

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