Found this liquid on concrete floor directly under metal flue in basement level, it appears to be milky/clear and oily in texture, so my question is, do any of you have knowledge of what this might be?
Can be several causes .Not enough info.
Don’t need any more information.
You have combustion gas condensate forming in a metal flue pipe because of insufficient heat in the flue pipe.
Condensate is highly corrosive.
If condensate is leaking out of the flue pipe you also have a likelihood of combustion gas also being discharge from that flue pipe.
You must determine the draft capacity of that flue pipe. You must determine the temperature and dew point of the flue gases.
If you don’t want to do this you simply post What you posted here and have someone take care of it. It is a problem.
By the way, do not listen to Bob because he doesn’t understand the laws of thermodynamics and psychrometrics concerning infrared toys anyway.
David nailed it on the head but just report that the issue has to be evaluated/corrected by a licensed HVAC tech!