His representative, Bektas Demirtas, told German publication Express: “It is true that Tottenham have registered their interest with me.”
Bayer reportedly want £21.4 million for the Turkish intentional attacking midfielder according to Bild.
The 22-year-old has another three-years remaining on his contract and the German giants are prepared to hold off accepting a deal until their valuation is met.
Spurs are not alone in their pursuit of Calhanoglu as La Liga giants Atletico Madrid are also in the race as and TalkSport report that North London rivals Arsenal are keen on the attacking midfielder.
The young attacking midfielder was snapped up by Karlsruhe aged 15 and rose through the youth ranks before being promoted to the senior side towards the end of the 2011-12 season.
Hamburg ended up signing Calhanoglu for €2.5m in 2012 and he started to make a name for himself, scoring several outrageous free-kicks.
Bayer Leverkusen snapped him up for €14.5m in 2014. Calhanoglu has gone onto made a name for himself as one of the most feared free-kick specialists in European football scoring 11 direct set-piece goals in the Bundesliga.