Borussia Dortmund CEO Aki Watzke has said he believes Bayern Munich have set out to "destroy" the club.
Dortmund won back-to-back Bundesliga titles in 2011 and 2012, and thrashed Bayern 5-2 in the 2012 DFB Pokal final in Berlin.
But Jurgen Klopp's side lost the 2013 Champions League final to the Munich club -- and then lost star names Mario Goetze and Robert Lewandowski, who moves in the summer, to their rivals.
And Watzke told Die Welt: "They have now retaliated. They want to destroy us. Not as humans because they don't like us, but to permanently switch us off as a direct competitor by taking our players so that we no longer constitute a threat for them.
"That's legitimate, and we have to live with that."
He added that, financially, Dortmund were not able to compete with Bayern. "When they offer double the wages you have no chance," he said of the Lewandowski and Goetze transfers.
Bayern, who ran away with the Bundesliga title last season, have not lost any of their last 43 league games and are already 17 points ahead of Dortmund.
"There is currently no other league that is dominated by one club like the Bundesliga," Watzke added. "These are not Spanish proportions, but Scottish proportions."
Dortmund, who completed the transfer of 21-year old Serb Milos Jojic on deadline day, plan to invest more in the summer, Watzke stressed.
"We will do a lot. Let’s see what we'll get for our money," he said. "We still have room to increase our salary budget."