Wolfsburg have never hidden their desire to land the Belgian, whilst Bayer chief Rudi Voller has now confirmed they are very much in the mix to land De Bruyne.
"We made no secret of our interest in Kevin De Bruyne right from last summer," Voller told Sky Deutschland.
"There are many clubs interested in him.
"Regardless of our league position, we're always looking for new players.
"It's possible that we do sign somebody this winter, but then again, we could go into the second half of the season with the same team and look to do something next summer.
"If you do anything, then it's got to be a top alternative to what we've already got here."
Whilst Leverkusen and Wolfsburg are heading the chase, a host of other clubs are following De Bruyne, who is anxious to play first-team football in order to secure his spot in Belgium's World Cup squad.
Borussia Dortmund, Hamburg, Schalke and Werder Bremen, where he spent last season on loan, are also keen.
Atletico Madrid are also reported to have made contact about a possible deal, whilst in England, Aston Villa have also been linked.
But the Bundesliga appears De Bruyne's most likely destination, while Chelsea do have to decide whether to let him leave on loan or sell him on a permanent basis.