BONN � Simon Wiesenthal, 87, was being treated in a Viennese hospital Friday as a controversy raged over his record and pedigree as the world's most celebrated Nazi-hunting sleuth.

It followed the screening of a prime-time German television documentary that featured interviews with rival Nazi-hunters from the United States, France and Israel's Mossad intelligence service, all of whom were scathing of Wiesenthal's 50-year career in tracking down war criminals.

Wiesenthal's lawyers were understood to be considering legal action against the makers of the 20-minute Panorama documentary broadcast by the Hamburg-based North German Broadcasting television network on Thursday night.

"Incompetent," "unprofessional" and "tragic figure" were some of the milder terms used to describe Wiesenthal.  He was accused of inflating his own role in the Mossad capture of Adolf Eichmann, one of Hitler's key henchmen, in Argentina, and of providing wrong and useless information in the hunt for Martin Bormann and Nazi doctor Josef Mengele, who performed gruesome medical experiments on concentration camp inmates.

The program also revisited the bitter row surrounding former Austrian president Kurt Waldheim, who was cleared of war crimes in the 1980s but found to have covered up his wartime past as a German intelligence officer.

The sensitivity of the subject and its prime-time screening in Germany led to intervention by the office of the chancellor, Helmut Kohl, after Wiesenthal apparently contacted Kohl to express concern about the program.

All of those interviewed are known to have waged long-running feuds and vendettas against Wiesenthal.  They included Beate Klarsfeld, the French Nazi-hunter; Isser Harel, the retired Mossad chief who headed the Eichmann capture operation and has been angry for decades over Wiesenthal's perceived effort to take the credit for the spectacular kidnapping; and Eli Rosenbaum, the head of the U.S. justice department's office of special investigations, whose 1993 book, Betrayal, is an indictment of Waldheim and Wiesenthal's role in the Austrian scandal.

The centre of Wiesenthal's one-man operation, a dingy cramped office in central Vienna, was inundated with faxes from anonymous neo-Nazis Friday, his secretary said.