Lewandowski, 24, has been strongly linked with a move to Treble-winners Bayern, with the club having already reached an agreement to sign Mario Gotze from Dortmund.
But it seems Dortmund have dug their heels in over a second big-name sale to their Bundesliga rivals, who defeated them 2-1 in the Champions League final at Wembley last month.
The club's CEO, Aki Watzke, is quoted by Bild as saying: "Robert Lewandowski will definitely not make the switch to FC Bayern in 2013. That's final. We have informed Robert and his agents now."
Their general manager, Michael Zorc, has also told Ruhr Nachrichten: "We have informed the player and his agent that we will object to a switch to FC Bayern this summer. He has always been very professional so far. He has a flawless character"
It remains to be seen, however, if the announcement will ensure Lewandowski remains at the Westfalenstadion, with speculation already suggesting the Poland international will seal a move outside of Germany.
The likes of Manchester United are said to be admirers of Lewandowski's talent, with the striker, who signed for Dortmund from Lech Poznan in 2010, having scored 36 goals during the 2012-13 season.