The Geneva prosecutor, Bernard Bertossa, says more prominent Germans profited illegally from the sale of the Leuna refinery nearly a decade ago than was previously thought.
Bertossa's office has conducted a lengthy investigation into the sale.
In an interview on Berlin radio, Bertossa said businessman Dieter Holzer and former state secretary Holger Pfahls weren't the only ones to have received kickbacks when the refinery, located in eastern Germany, was sold in 1992 to France's Elf Aquitaine.
"There are troubling facts which lead me to believe that many well-known personalities received some benefits from the Leuna sale," Bertossa said in the German radio interview.
More than two dozen named
The prosecutor's office recently transferred the results of its investigations to the German authorities. According to the Hamburg weekly, "Die Woche", the documents contain the names of 24 politicians belonging to the Christian Democrat Union (CDU) and five members of the Christian Social Union (CSU).
Some of the politicians have held key positions in regional and national governments. They include one current and two former heads of states, eight former federal ministers and five previous state secretaries.
"Die Woche" mentioned the names of former CDU members, including two treasurers, a plenipotentiary and a tax adviser.
German federal prosecutor Kay Nehm said that "German justice must take action" in the Leuna case to investigate the Swiss claims. In an interview in the newspaper "Sueddeutsche Zeitung", Nehm indicated that there was sufficient material to warrant further action.
Swiss bank ties alleged
The people named were identified because they have or had Swiss bank accounts according to Die Woche. If they were attempting hide income, they could only be indicted for tax fraud by the German authorities.
Bertossa said the German authorities must investigate the sale of the refinery. He also renewed an offer to help if needed.
The Germans have begun to sift through the Swiss documents, two thirds of which will have to be translated from French. The federal prosecutor's office will then decide whether to deal with the case itself, or to transfer it to regional prosecutors.
Elf is alleged to have paid out DM80 million in kickbacks to German politicians to obtain the Leuna deal, according to investigators.
swissinfo with agencies