They had their usual standard story for each time the Ministry paid a visit to the muggles. Most of the details were kept highly confidential, but the usual tale that went around was that the M.O.M industries was an offshore giant that traded goods of some kind that the government treasured too much to disclose to the public. Any aurors or employees who visited had to ensure they were wearing muggle outfits, so there were no raised eyebrows. Or rather, the only eyebrows raised were because people from the top-secret place had come to talk about their top-secret thing.