Let's suppose we have a small country in a forgotten corner of the world.
And let's assume that a local English-language website appeared out of nowhere, with no ads, hosted on the same server with official government sites (even the same IP!), has obviously the same designer and uses the same software with those government sites.
That news source could even disagree with the government on minor point, in order to look independent and reliable. The only references in the mainstream press (e.g. The Economist) call it an "astroturfing" attempt of the government.
Would you call this source "reliable", worthy to be used as for references in Wikipedia?
And if there's a wikipedian who really loves this source, who agrees almost 100% to it and adds it to dozens of articles, reverting any attempt to remove it, what should we do?