The Germany international made the switch to Jurgen Klopp's outfit on a five-year deal in July 2012, after the club agreed a fee reported to be in the region of €17.1 million with Borussia Monchengladbach.
Reus has quickly developed into a pivotal player for Dortmund and the 24-year-old boasts seven goals in 12 Bundesliga appearances this season.
His impressive form has led to rumours of a move to the Premier League, with Manchester United or Arsenal, or Ligue 1 champions Paris Saint-Germain.
Dortmund executive Hans-Joachim Watzke has now confirmed there is a release clause in Reus' contract, with reports suggesting the figure is approximately €35 million.
"Marco Reus possesses a release clause option in his current contract at our club," Watzke told SPORT1media. "He could leave our club due to that.
"He is, however, the only player in our first-team squad that has such a contract clause."
Dortmund's hopes of reclaiming the Bundesliga title from rivals Bayern Munich were damaged by a 2-1 defeat at Wolfsburg on Saturday, which put them four points adrift of Pep Guardiola's table-toppers.
A 1-0 setback at home to Arsenal has also left Dortmund's UEFA Champions League hopes in the balance. They trail Arsene Wenger's men and second-placed Napoli by three points with two Group F fixtures remaining.
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
‘He’ll still be playing at 40 at a good level because he’s in such good shape and looks after himself so well. He does everything to be a top professional’: Ex-Liverpool coach insists Mohamed Salah has plenty more miles in the tank
