Public prosecutors here said on Tuesday they were investigating executives of the drugs giant Bayer in the scandal surrounding the company's anti-cholesterol treatment Lipobay or Baycol.

A spokeswoman for the prosecutors' office in Cologne said that the investigation would determine whether executives had negligently broken the German drug law by bringing "dubious" drugs into circulation. "The law states that it is forbidden to bring dubious drugs into circulation, even negligently, and that is the allegation we're investigating here," the spokeswoman told AFP.

Further details would be made available at a news conference later on Tuesday, she added.

Last month, Bayer was forced to withdraw Lipobay, previously one of its best-selling drugs, after conceding that more than 50 deaths might be linked to it.