I beg to differ. Reputable auction houses do it as well. And the auctioneers act all prim and proper and seem to loathe the ghosts when you ask them about it, but the ghosts still get their deposits back. How do you reckon that happens without the auction house colluding with them?

Bank lelong or private auction? Bank lelong is impossible. Unless the bankers, lawyers, auctioneers and judge all involved. I almost never seen it before. Only time it happens is if there is a legitimate reason like owner dispute.
If is bank lelong most likely borrower settle lor. Bank call off cost them money. Won't simply call off.

There are syndicates that tried to bid rig. That is rampant. But getting back the deposit is simply not possible. If that happens the bank can get sued in court. Next time if you see that happen, complain to the lawyer, banker or the judge. At least two of them have to be on site during the auction.

PM me which auctioneer that does it. I am in the industry.
Again, very hard to happen. I am not saying 100% it is not going to happen but I have been to more than 100 auctions and have never seen it happen.

The whole lelong industry is shrouded with misconceptions and mystic. The only thing that is true is bid rigging. Even so, that is being stamped out with e lelong.