German prosecutors have alleged former Tour de France winner Jan Ullrich has used banned substances since 2003.
Ullrich maintains he has not used outlawed drugs
Ullrich was sacked by his T-Mobile team before this year's Tour after being implicated in a Spanish doping probe.
"These are not conclusions we have come to ourselves - they are supported by reports from Spanish police," said a spokeperson for the Bonn prosecutors.
Swiss cycling authorities are also currently investigating the rider who continues to protest his innocence.
German prosecutors are also investigating Ullrich's former team-mate Oscar Sevilla and sporting director Rudy Pevenage, also both sacked by T-Mobile.
Madrid prosecutors said earlier this week that they hope to hear submissions from all the riders implicated in the blood-doping probe over the next month.