Two more WorldTour pro cyclists have reportedly been linked to the Operation Aderlass blood doping scandal, according to a report by German broadcaster ARD.

To date the operation, launched earlier this year by police and anti-doping officials in Austria and their colleagues in Germany, has involved 23 athletes, a number of them from cycling.

The names of the latest two cyclists to be linked to the ongoing investigation have not been made public, although both are said to be German.

However, ARD says that it has passed their details on to prosecutors investigating the activities of Erfurt, Germant-based Mark Schmidt, former doctor to the Gerolsteiner cycling team.

Doping scandals involving that team as well as T-Mobile back in the late 2000s led to both folding as sponsors pulled out, and for several years the Tour de France was not broadcast in Germany.

It took the best part of a decade for the damage to cycling’s reputation in Germany to be repaired, and the country can ill afford a similar scandal.

Just last month world cycling’s governing body, the UCI, requested that the Cycling Anti-Doping Foundation (CADF) “proceed with necessary reanalyses of samples taken during the 2016 and 2017 seasons” due to information that had come to light as part of Operation Aderlass.

> Operation Aderlass: UCI orders retest of samples from 2016-17

Among cyclists already sanctioned as part of the operation are retired Italian pro Alessandro Petacchi, winner of Milan-San Remo and the points jersey at all three Grand Tours, who was banned for two years in August.

The Austrian riders Stefan Denifl and Georg Preidler and the Croatian, Kristijan Durasek, were all handed four-year bans, while Slovenian riders Kristijan Koren and Borut Bozic both received two-year bans.

In May this year, Danilo Hondo, the retired former German road race champion, admitted to ARD that he had paid Schmidt €30,000 for blood transfusions in 2011, his confession leading to him being sacked as a coach to the Swiss national cycling federation.

Operation Aderlass – the name means ‘bloodletting’ in German – first hit the headlines after a number of arrests were made at the Nordic World Ski Championships in Austria in February.

In its latest update on the investigation, which aired last night, ARD claimed that Schmidt worked with athletes in a number of sports and that contact, often at motorway service stations, would be arranged via text message using Slovenian SIM cards to try and keep the conversations secret.

The doctor would introduce himself by SMS to potential new clients with a message saying, “I’m the guy with the cool bag,” it is alleged.

A number of athletes who competed at last year’s Sochi Winter Olympic Games in South Korea were clients of Schmidt’s, the broadcaster claims.

It says that given the impracticalities of taking a flight to South Korea with blood bags in his possession – something that would be bound to raise suspicions – Schmidt hit upon a novel solution.

According to the broadcaster, the athlete would be injected with treated blood close to Frankfurt Airport shortly before departing for the Games, and would undertake the long-haul flight with excessive amounts of blood in their bodies, with the obvious health risk that brings.

Once in South Korea, the amount of blood they had been supplied with would be removed, then reinjected shortly before they competed.

Last week, public prosecutors in Munich brought charges against Schmidt and four assistants accusing them of “commercial and, in some cases, banned use of prohibited doping methods” or abetting such methods, and also charged the doctor with suspicion of causing dangerous bodily harm.