Odemwingie was pictured outside Loftus Road on Thursday evening, despite his club revealing they had not given him permission to speak to QPR.
QPR boss Harry Redknapp claimed "wires got crossed" after the move failed to go through before the transfer window slammed shut.
West Brom chairman, Jeremy Peace, has now issued a statement admitting the whole situation was an "unsavoury affair" for all involved.
"This evening's developments have brought a conclusion to what has been an unsavoury affair," he said.
"As our Sporting & Technical Director (designate) Richard Garlick has repeatedly said in recent days, we had no need or desire to sell our core players.
"The only way we would have considered letting Peter leave was if an acceptable offer was forthcoming and if we had found a suitable replacement at relatively short notice.
"Neither materialised and, in the end, the matter became a point of principle as much as anything.
"Peter has acted wholly unprofessionally. He must now accept the fact he remains under contract for a further 18 months and has to focus on his Albion commitments."
Odemwingie is now faced with going back to West Brom looking for forgiveness, having spent the best part of the last week complaining on Twitter about their refusal to allow him to leave.
He had, though, initially thought that was in the past, telling reporters from his car: "It's fine. West Brom was my home but this is a new chapter. I love West Brom and always will.
"I am optimistic. A few good players have arrived here (at QPR) and I am happy with the trust Harry Redknapp has in me.
"The last few results have given us a chance to stay up. I don't think the owners will bring in so many players if they don't think it will happen.
"I hope West Brom are happy with what they will get and they hope to get players themselves."
Rangers boss Redknapp said he had sympathy with the player, telling Sky Sports News: "I think he probably felt that the deal had been agreed between the clubs and it hadn't and it was all a mix-up really.
"I feel sorry for the lad and the way the whole thing's turned out. It wasn't any of our doing. I think he was maybe advised that he should turn up here and that the club had made an offer and the offer had been accepted. The wires got crossed somewhere."