The 32-year-old spent six years with the Bundesliga outfit before moving to the Hammers in August 2011.
But the German club are looking in to the possibility of bringing the Ivory Coast international back to where he was a firm favourite with the Die Rothosen faithful.
Sam Allardyce has already seen George McCartney and Pablo Armero leave the club this summer, and it’s understood he is reluctant to allow another full-back to leave as he attempts to prepare a side capable of delivering the attacking football demanded by the Upton Park hierarchy.
But Demel has already hinted that he would welcome a move away from the club this summer, despite Allardyce considering him as an important member of the first-team.
The defender has made 75 appearances in all competitions for West Ham, scoring one goal.