Why would a bank originally MLS a REO property for only a few weeks, then put it up for auction?

Prime property-great condition. Title search showed foreclosed with legal lien from previous owners. (foreclosed –sold - but still in Court with bank?) Will lien be removed if I get it at auction?

Because they want to sell it. Most reo's are sold free and clear. The bank's mtg/lien no longer exist and any junior liens should have been wiped out by the foreclosure.