If one reads around MOB forums, it appears as if a number of "FSU investigators" or other background check providers online have been busted for their inconsistent or else fraudulent services.
Even some of the most "established" charachters ( forget about small-time scammers who ask you to wire money and then disappear ) are somewhat shady: multiple identities or contested identities; no walk-in facilities; mystery business practices; mixed reviews leaning on the bad side, whatever.
As a plus, some claim it is "impossible" to run a proper "investigation" business in the open in some FSU countries, due to some "law" ( again: other say this isn't true ).
So it could just be another scheme to extract money from gullible people.
Buyer beware.