London - London's Metropolitan Police have arrested a 17-year-old male for a "racially aggravated public order offence" during the first leg of the League Cup semi-final between Tottenham Hotspur and Chelsea at Wembley, a force statement said.
It was understood the language used was allegedly anti-Semitic.
"Police have arrested a 17-year-old male for a racially aggravated public order offence at tonight's @SpursOfficial v @ChelseaFC," said a statement from the Met Police's Football Unit on Twitter.
"The male is currently being dealt with at a North London police station."
The arrest took place at approximately 19:40 local time , some 20 minutes before kick-off.
Before Tuesday's match, both London clubs warned fans about their behaviour.
Chelsea supporters have been under the spotlight in recent weeks after a number of high-profile incidents, including a derogatory chant about Spurs supporters that featured alleged anti-Semitic language at a Europa League match in Hungary last month.
"Historically, a small minority has used the Tottenham fixture as licence to use anti-Semitic chants, noises and gestures," said a statement from Chelsea, whose Russian owner Roman Abramovich is himself Jewish.
"Our position is clear - this is no excuse for abusive chanting or behaviour and it will not be tolerated."
Meanwhile a Spurs fan was banned and fined for throwing a banana skin at Arsenal's Pierre-Emerick Aubameyang during the North London derby in early December.
A statement on Tottenham's website reminded ticket holders that "foul, abusive, homophobic or racist behaviour will not be tolerated".
Yet many Tottenham fans who are not themselves Jewish have adopted the word "Yid" - a derogatory alternative for "Jews" - as a badge of honour in recognition of the strong support their club has long received from the Jewish community in north London.
But last week both the World Jewish Congress and the Board of Deputies of British Jews, urged Spurs to oppose the use of the word "Yid" by their fans.