Granit Xhaka is denying using racially abusive language towards an airline staff member at Heathrow Airport on Monday night, Goal understands.
The Arsenal midfielder, 24, was interviewed by police after voluntarily attending a west London police station.
Switzerland international Xhaka was at Heathrow’s Terminal 5 where he was saying goodbye to his fiancee’s footballer brother Leonard Lekaj, who had arrived late for his flight back to Germany and was not allowed to board.
The alleged abuse was then directed at a staff member, although Goal understands Xhaka denies saying the “f*cking white bitch” words attributed to him by the complainant.
Lekaj, 26, plays in the sixth tier of German football and had been visiting London over the past few days where he witnessed Xhaka get sent off from the player’s private box at Emirates Stadium during Sunday’s narrow 2-1 win over Burnley.
“Police were called at 19:29hrs on Monday, 23 January following an allegation that a member of staff had been racially abused at Heathrow Airport, Terminal Five”, the Metropolitan Police said in an official press statement.
"The allegation was made by a third party. Officers attended and spoke with a man in his 20s. He was not arrested.
"He voluntarily attended a west London police station where he was interviewed under caution. Enquires continue.”
A source close to the player has told Goal that Xhaka denies all wrongdoing, instead insisting he was provoked, and says media reports quoting alleged racial comments towards an airline staff member are "not true".
Goal understands that several members of Xhaka's family, including a close cousin from Kosovo, are expected to arrive in London tomorrow as a show of support.
The ex-Borussia Monchengladbach player is believed to be frustrated that he was red carded at the weekend for the second time this season.
Meanwhile, Gunners captain Per Mertesacker organised and a team bonding meal at Prime Steak & Grill in St Albans on Tuesday night.
The meal was organised before the news of Xhaka’s police interview but photos show him looking happy alongside team-mates including Olivier Giroud and Laurent Koscielny.