Brentford could face disciplinary charges from the Football Association after referee Grant Hegley's report of Tuesday's 1-0 win over Tranmere. Safety officer Alistair Hill confirmed the report mentions "aggressive and threatening behaviour" by Bees fans.
It also cites alleged racist comments made by fans to a Tranmere player.
"I regret to say this is not the first time this season we have been under the spotlight following a referee's report," Hill told Brentford's website.
"As a result, we can expect representatives from the FA to attend our next match.
"The club will now have to ensure there are sufficient stewards deployed for the remainder of this season to make sure this does not happen in the future, again at extra cost to the club.
"The club could also be fined or have other sanctions imposed which the FA feel is necessary. "Together with the police, we will now study the CCTV footage of Tuesday's game to see if we can identify any such behaviour.
"Manager Martin Allen has stressed the important part the crowd's passion plays - and this can be intimidating to the opposition.
"But for the good of the club, supporters are reminded that to overstep the mark could have a costly and damaging effect on the respect that Brentford Football Club enjoys."