Can estate agents use "ghost bidders" to drive up price of house?

Well the house went up and up just like an auction untill it was 6k over the asking price so we did not go any higher the estate agent said its because its a repossesion and the bank wants more
No, this is not the reason. Every seller sells for the maximum price they can achieve. Wouldn't you? If there are two buyers interested then they keep going back and forth to each bidder with the highest bid like an auction until one backs down - as you did. Problem is that you have no way if knowing of the bids are real.

You are free to make any offer above or below the asking price. If someone has already offered the asking price then they won't be very interested in a bid below that level, will they? 'Under offer' just means that they have a serious offer and are negotiating a contract but no deposit has been paid. The agent knows that the sale may well fall through and the buyer can pull out anytime, so if the other buyer pulls out you might still get it for the price you want.
 
Just seems to take the **** i had to close bonds just to prove i had the funds in place to buy the house when i went to view it and take time off work to view it and there was no mention on the estate agents site saying it was under offer untill i went from a 75k asking price upto 80k. And guess what less than 24 hours of me pulling out its back on all sites up at 75k? then this other house i am supposed to view tommorow the apointment was made to view it yesterday morning then went off there website in the afternoon and said its sold on another ? so why mess people about getting them to take time off work to view a sold property? I am now starting to think all estate agents are just after a commision for stitching you up with a mortagage and in this age cash dont matter as they all seem peed off when you tell them you dont need a mortage.
 

Very interesting, thanks for that. I'll be on the look out.