Moscow - (Pie-in-the-Sky): The craft was first seen in Russian airspace at the April 2010 downing of a Tupolev Tu-154 that claimed the lives of the Polish president and his entourage.
Last week's reports of its Moscow fly-past were hurriedly withdrawn after Prime Monster Vladimir Putin ordered a nationwide news blackout.
Kremlin insiders speculated today that Putin fears his radical Aliens Treaty could bomb amid public hysteria about the craft.
The pact proposes a timetable about extraterrestrials' sovereignty issues in the much disputed oil-rich territories of the Arctic.
Online reports that Russian Navy ice-busting survey subs tunnelling beneath the frozen Arctic Circle waters 'may have disturbed a UFO hangar' have included video footage posted on the YouBoob! channel.
"The last thing the Kremlin wants is a hysterical turf war with these alien bastards," a government source commented today.
The Black Widow Brigades may be an renegade ex-KGB offshoot out to oust Putin and his sidekick Medvedev.