The four doctors implicated in the Freiburg University Clinic investigation have been named by the Badische Zeitung newspaper.
According to the publication, Andreas Blum, Stefan Vogt, Stephan Prettin and Carsten Temme are being investigated for their role in doping of T-Mobile riders during the past decade, accused of "taking additional money for the practice of the medical profession without the approval of their employee".
The newspaper reported that Blum left the Clinic in 2006, Prettin is still employed there while Vogt was fired in 2008. Temme's whereabouts were unknown.
Chief prosecutor Wolfgang Meier has only confirmed that there are four doctors involved in an expanded investigation, refraining from disclosing the names of those under scrutiny.
It's also been revealed that prosecutors looking into organised doping with Team Telekom/T-Mobile and the University of Freiburg Clinic are also investigating three former team leaders, for conspiring to commit personal bodily injury, although their names are yet to be announced.