Does anyone know whether there has been a case or two where an
asylee's status of "Asylum granted" was revoked upon finding evidence
that the beneficiary's asylum case was fraudulent? example of
evidence would include the beneficiary entering the country that he/
she claimed to be dangerous for his/her safety through the back door
(via crossing the border with no need to use the white passport issued
by the US government that would normally be required at custom check
points in the airports).

If so, I'd like to know. I am asking this to determine how seriously
immigration office take such case where evidence can be shown. Unless
the immigration takes this seriously, I won't bother reporting someone
whose fraudulent asylum case was approved and received green card.
That person has recently entered the country that she claimed to have
a danger to her life through the back door via a neighboring country.
I can find proof that she was in that country because she would have
pictures that would do her in. But, would the immigration be serious
to deport and ban her from US if I provide such evidence?