Bayer Leverkusen general manager Rudi Voller has slammed Borussia Dortmund for signing Sokratis Papastathopoulos despite his side having an "agreement" with Werder Bremen.

Voller said that Dortmund's behaviour following their disgust at Bayern Munich's recent capture of Mario Gotze makes them look hypocritical.

"We had an agreement with the player and also with Werder Bremen, too," Sky Sports News quotes Voller as saying.

"Now Papastathopoulos has cancelled the deal and joined Borussia Dortmund. This is very annoying from our point of view.

"Everyone knows that [Dortmund] were aggrieved by the news that Mario Gotze joined Bayern Munich, and then in this case they are hypocritical. I can smile at this. That's how things are in business."

Dortmund face Bundesliga rivals Bayern Munich in Saturday's Champions League final at Wembley.