Prosecutors have asked a Spanish judge to call 50 riders who are possibly connected to an alleged blood-doping ring headed up by Spanish doctor Eufemiano Fuentes to give testimony, Spanish daily El País reported Thursday.

The prosecution wants the 50 riders to give testimony under oath or face possible perjury charges. The riders won't face any legal charges in Spain, as the national anti-doping law isn't in effect untill November 1.

Investigators are keen to gain witness testimony as some insiders say that the existing evidence won't be sufficient enough to convict Dr. Fuentes and the hematogolist José Luis Merino Batres. Fuentes and Merino Batres could face charges of endangering public health, but so far no charges have been filed.

Meanwhile state prosecuter Fred Apostel confirmed  that German investigators have asked Spanish authorities for more material about the Puerto case. The state-prosecution of Bonn is investigating the case after a German professor filed fraud charges against Ullrich and Sevilla.

The second hearing of Ivan Basso will not be held on September 12. Italian sport authorities re-scheduled the hearing, Basso's second hearing will now be on September 29.  Basso spoke with a reporter of the Italian news agency ANSA, saying: "I understand the judiciary have changed the date, but I remain respectful and confident as always, but at the same time I can't wait to close this matter positively". He continued by saying: "I repeat what I've already said: I'm not involved in this business. I'll keep on saying it. I'm respectful of everybody, but I would like to be listened to and believed."