German prosecutors charged Friday that former Tour de France winner Jan Ullrich has been taking banned substances since 2003.

Ullrich was sacked by his T-Mobile team and kicked off the Tour this year after being implicated in a doping probe launched in Spain.

In July, German officials took up the investigation, which linked Ullrich to tainted Spanish doctor Eufemiano Fuentes, and now they seem convinced that Ullrich, who continues to protest his innocence, is guilty.

"Since 2003 unauthorized products were bought by Ullrich," said a spokesperson for Bonn prosecutors. "These are not conclusions we have come to ourselves: they are supported by reports from the Spanish police in response to our inquiries into the investigation. We requested collaboration from the Spanish police to verify these findings."

Bonn prosecutors are also investigating Ullrich's former teammate Oscar Sevilla and sporting director Rudy Pevenage, both of whom were also sacked by T-Mobile and kicked off the Tour after implication in the Operacion Puerto probe.