In this context, "Ex-Tour de France winner" doesn't mean he won and then was stripped of the title.
He won the 1997 title, which he still has.
Although German, he rode for the Swiss cycling federation, and when the swiss started investgating him for doping in 2006 when his name was linked to a massive doping scandal in Spain, he changed federations which eventually killed the swiss investigation as they had no jurisdiction.
He was finally banned in 2012 and all results since 2005 voided. But he got to keep his Tour victory (1997) and olympic medals (2000)
This story from 2013 doesn't seem to have had any consequences:2013: French Senate releases positive EPO cases from 1998 Tour de France
Zabel, Ullrich, Pantani and Livingston all listed
Pantani won in 1998 with Ullrich 2nd.
The Senate ordered that no results would be stripped as a result of their report: "Nobody will face sanctions. We aren’t policemen. We aren’t magistrates. We haven’t noted absolute lies but put-offs and self-censorship," they said.
Andrea Tafi, Erik Zabel, Bo Hamburger (twice), Laurent Jalabert, Marcos Serrano, Jens Heppner, Jeroen Blijlevens, Nicola Minali, Mario Cipollini, Fabio Sacchi, Eddy Mazzoleni, Jacky Durand, Abraham Olano, Laurent Desbiens, Marco Pantani, Manuel Beltran, Jan Ullrich (twice), Kevin Livingston (twice)
Ermanno Brignoli, Alain Turicchia, Pascal Chanteur, Frederic Moncassin, Bobby Julich, Roland Meier, Giuseppe Calcaterra, Stefano Zanini, Eddy Mazzoleni, Stephane Barthe, Stuart O'Grady, Axel Merckx
18 positive, 12 "suspicious"
The re-test took place in 2004 but the results weren't released until 2013