What a surprise. A real estate agent in Melbourne has been found to have been engaged in illegal misleading practices involving negotiations after an auction. The real estate agent told the bidder that someone else had made an offer at a certain price, when in fact that was not the case. See The Age.
I am aware of situations in Queensland were real estate agents working for well known agencies and who are selling apartments engage in similar misleading conduct, even producing fake contracts.
This decision also reminds me of a case from New Zealand where the real estate agent sold the house to a regular "client", who then on sold the house for a profit. The agent was found not to be acting in the best interest of the seller, and the bird-dog relationship with the buyer was something material that should have been disclosed to the seller. See decision and article.