Arsenal are to investigate academy coach Mark Arber as a "matter of urgency", following reports that he may have breached the FA's rules on betting.
Arsene Wenger signed Mesut Ozil on transfer deadline day for £42.4 million and when the move was officially confirmed, Arber took to Twitter to have his say on the signing.
On his personal account, Arber suggested he had bet on Germany midfielder Ozil's move to the Emirates, writing: "Lovely bit of 14-1 Mesut."
An Arsenal spokesman responded to Arber's tweet, saying: "All our employees and workers are well aware of their responsibilities in this respect and we are looking into this as a matter of urgency."
If Arber is did bet on Ozil's Arsenal arrival, his future with the north London outfit could be at risk.
The Gunners' 35-year-old academy coach would have broken the terms highlighted in the Football Association's guide to betting rules.
The FA regulations clearly state: "You are not allowed to place a bet on a game or competition in which you have any influence, either direct or indirect.
"The above includes all bets related to the following: Any other events involving your club or other clubs playing in the same league competition (such as next manager markets)."
Arber is not the first to be caught up in a betting scandal, with Andros Townsend - who plays for Arsenal's north London rivals Tottenham - reportedly charged for placing large bets on Premier League matches back in May.