German authorities secured DNA samples from former Tour de France winner Jan Ullrich in a raid earlier this week on his Swiss residence, according to a report released on Thursday.

Germany's Sueddeutsche Zeitung said in an advance release of its Friday edition that authorities had secured samples of the German rider's DNA that were to be compared with frozen blood seized at a Madrid clinic as part of a doping investigation that saw Ullrich and eight other riders forced to withdraw from this year's Tour.

Authorities could not immediately be reached to comment on the report.

On Thursday, Germany's Federal Crime Office said Ullrich's main residence in Switzerland and nine other homes and offices were searched as part of a fraud investigation by Bonn prosecutors in connection with a Spanish doping probe linked to doctor Eufemiano Fuentes.

Ullrich was not at home during the raid.

Five people in Spain _ including Fuentes and another doctor, Jose Merino Batres _ were arrested and charged in May when police seized drugs and frozen blood at a Madrid clinic. The samples were thought to have been prepared for performance-enhancing transfusions.

German officials are investigating if cyclists, who were not identified, received payments they would not have if their commercial sponsors had known about the suspected doping.

The German probe is based on the Spanish investigation of riders suspected of doping.

A Spanish Civil Guard police report on the investigation cited more than 50 cyclists. Nine riders, including Ullrich, Ivan Basso and Francisco Mancebo, were forced to withdraw before the start of this year's Tour de France.

Ullrich, who won the 1997 Tour de France, was fired by T-Mobile. He has denied any wrongdoing and has declined to take a DNA test.

© The Canadian Press, 2007