Spurs issued a statement on social media to confirm Christopher Aurier had been killed in the early hours of Monday morning.
Reports in France had detailed how he had been shot after attending a nightclub in Toulouse.
Christopher Aurier was 26 and had previously been on the books of Lens, while also playing for other clubs in the French lower leagues.
A Tottenham statement read: "The club is deeply saddened to confirm media reports that Serge Aurier’s brother passed away in the early hours of this morning.
"Everybody at the club sends their sincerest condolences to Serge and his family. Our thoughts are with them all."
Serge Aurier, 27, played the full 90 minutes of Tottenham's derby win over rivals Arsenal in the Premier League on Sunday and is captain of the Ivory Coast national team.
His younger brother was also a citizen of the west African country.