The German authorities claim DNA analysis proves blood samples confiscated during a Spanish investigation into a doping ring belong to Jan Ullrich.
The German retired in February following his dismissal from the T-Mobile team in June 2006 after it was alleged he was implicated in 'Operacion Puerto' - a doping case against Spanish doctor Eufemiano Fuentes.
The case did not come to court but prosecutor Friedrich Apostel believes he has the evidence to connect Ullrich to codenamed samples seized by Spanish police.
Apostel told German TV channel n-tv: 'We had nine blood samples which we could compare to the DNA tests from Jan Ullrich. By doing this we could identify Jan Ullrich.
'It shows that the blood (Ullrich's) was stored there (with Fuentes).'
However, Ullrich's lawyer Johann Schwenn believes the samples do not offer conclusive evidence.
Schwenn said in a statement on the former Tour de France champion's official website: 'The plea (attorney) will take a close look at the report of the Federal Criminal Police Office.
'After the irregularities in the Spanish process and within the UCI, it is very possible that the alleged confirmation is a consequence of manipulation.
'There is no reason to change the strategy for Jan Ullrich's plea.'
