Franz Beckenbauer has hit back at a consumer group over claims that some of the venues for this summer's World Cup have serious safety problems.
Stiftung Warentest reported that four stadiums were "substantially" unsafe, while eight were "clearly" unsafe.
But Beckenbauer, president of the tournament organising committee, said: "I'm sick of all this 'we know best'.
"Stiftung Warentest may know about facial cream, olive oil and vacuum cleaners. They should stick to that."
Stiftung Warentest, Germany's leading consumer safety group, claims the grounds fall short of the necessary standards in areas such as crowd safety.
Stadiums in Gelsenkirchen and Leipzig, for example, were found to have a lack of sufficient escape routes for spectators.
Berlin, which will host the final on 9 July, was also criticised for its emergency escape routes.
But Christoph Meyer, a representative of the Olympiastadion Berlin GmbH, believes the recent work done on the stadium is satisfactory.
"We will obviously look at the results but in Berlin, we have a building that has lasted the test of time and was renovated between 2000 and 2004, according to regulations for buildings of historical significance," he said.
And Hans Rutten, business manager of the company responsible for the WM-Stadion Cologne, added: "I don't see this as a very serious study."