This is what happened:
A government drone, of some military or spy service, got snagged doing some mission at or near Gatwick and the police ended up with it, all broken, which they truthfully reported: "We have a damaged drone."
The government agency, a bit later, got ahold of the police leadership and said, "Hey, STFU about our drone, give it back, and issue some cover story so this thing dies, now."
Which they did.
End of story.