QPR have vowed to ban for life whoever threw a coin at assistant referee Stuart Burt during their Barclays Premier League win over Arsenal, and appealed to fans to help them identify the culprit.
Rangers have been scouring CCTV footage in a bid to punish the spectator who struck Burt on the back of his neck with a missile moments before the end of Saturday's 2-1 victory at Loftus Road.
The Football Association are understood to be aware of the incident - which occurred after Burt awarded Arsenal a stoppage-time free-kick in front of the Ellerslie Road Stand - and are supporting efforts by QPR and the police to bring the perpetrator to justice.
Rangers said in a statement on their official website, www.qpr.co.uk: "The club is aware of a coin-throwing incident that took place in the latter stages of Saturday's home fixture against Arsenal at Loftus Road.
"The club are now in the process of reviewing CCTV in an effort to identify those people responsible and will take the appropriate action once this process has been completed.
"QPR supporters are reminded that this is a very serious offence and anyone caught throwing an object onto the pitch - towards officials or players - will be issued with an immediate lifetime ban from Loftus Road."
Chief executive Philip Beard added: "Such behaviour is simply not acceptable at Loftus Road, or anywhere else for that matter.
"As a club, we will do everything possible to prevent such incidents happening again.
"The club appeals to any fans who saw the coin-throwing incident to come forward and assist our enquiries."
Supporters can provide evidence confidentially by texting the club's Stadium Control on 07557 435421.