Legal Question in Real Estate Law in California

Yes, but if you are doing it to push the price up of the winning win it is illegal to do that no matter who you are.

Family members of the homeowner can bid at the trustee's sale.

The only acceptable bids at a trustee's sale (except for the foreclosing beneficiary's opening bid) are those that can be immediately and fully paid by the bidder with cash or bank checks (preferably cashier's checks) in hand. Therefore bidders must individually "qualify" with the auctioneer before the sale-showing him/her the total amount of money each bidder brought to bid at the sale. Nobody is allowed to bid more than the amount of cash they actually brought to the sale.

There is no penalty for the bidders to push up the price, as the idea behind the auction is to get the best possible price for the property. Family members who bid must ralize that a bid, however, is deemed to be an irrevocable offer by that bidder to purchase the property being sold by the trustee for the amount of the bid.

If family members are bidding in an effort to buy the property to transfer back to the trustor/ borrower, beware that the law has held that the lien of the deed of trust reattaches to the property.