Albion are investigating a pre-match incident which saw excrement left in the away team's changing room ahead of their play-off exit to Crystal Palace.
Manager Gus Poyet emailed club employees insisting “someone should lose their job” over the security breach.
Poyet told employees: “I am angry that someone within this club could endanger our good reputation and stoop so low.”
Albion have today refused to comment on the incident other than to confirm it took place before the match. No players were involved.
The Argus understands embarrassed senior club executives apologised to Ian Holloway and Palace directors before and after the match and officially the following day.
Poyet suggested the guilty party might have, figuratively at least, scored an own goal for the Seagulls.
He added: "Did they imagine that this would affect the Crystal Palace players? Well possibly it did. It may just have fired them up more.
"Well someone made a very bad decison and I think it is time to stand up and take responsibility. Not just the culprit but those employees who are supposed to make our stadium safe and secure."
Poyet has also slammed the use of clackers in the stands for the match which Palace won 2-0.
The club left paper clappers on 28,000 seats ahead of the match.
Poyet told employees he did not blame the clackers for the result but felt it was “an extremely silly idea and the result was an annoying noise.”