Ok. I see the paranoia settling in ....
Award tickets bought through Krisflyer, which is ultimately singaporeair.com has the same policy as revenue tickets bought through the site. You need to produce the same cc as the time you bought the ticket. If you lost the card, you need to show documented and official proof that you lost/changed cards etc.
Award tickets through other airlines do not need to produce your cc's used for taxes etc. eg, DL, BD, LH etc