The sports doctor at the centre of the "Aderlass" international blood-doping trial is expected to be handed a lengthy jail sentence on Friday when a court in Munich returns its verdict.

The prosecution has recommended Dr Mark Schmidt, 42, receive a five-and-a-half-year prison term, and a ban from practising medicine for a further five years.

Schmidt is accused of masterminding an international blood doping ring which helped dozens of athletes -- mainly cross-country skiers and cyclists -- to cheat.

Blood doping is aimed at boosting the red blood cells, which allows the body to transport more oxygen to muscles, increasing stamina and performance.

Schmidt has been in custody since Austrian and German police made co-ordinated raids in February 2019, including swooping on the Nordic World Skiing Championships in Seefeld, Tirol, as part of Operation Aderlass - 'Blood-letting' in German.

Five athletes and two suspects were detained at the championships, two hours before the start of the men's 15km cross-country event. One Austrian athlete was caught undergoing a blood transfusion.

Schmidt was arrested at the same time during raids in Erfurt, central Germany, and he has been on trial in Munich since September.

Defendant Mark Schmidt (c) talking to his lawyer in court last week
Defendant Mark Schmidt (c) talking to his lawyer in court last week POOL / Peter Kneffel

His four co-defendants also face jail sentences.

In court last week, Schmidt expressed remorse, "I took a wrong turn, it's all my fault," and regrets involving his four co-defendants: "I am infinitely sorry that I dragged the other four into it".

During evidence, one of the co-defendants told how she had travelled to venues around Europe by car to give athletes doping supplies, which each time earned her 200 euros ($243).

Initially, the list of events affected by the blood doping ring was impressive, including competitors at the 2014 and 2018 Winter Olympics, the 2016 Rio de Janeiro summer Olympics and 2018 Tour de France.

On Tuesday, Austrian cyclist Stefan Denifl became the latest athlete jailed due to the smashing of the Aderlass ring, when he received a two-year sentence, 16 months of which will be suspended.

However, contrary to what anti-doping authorities had hoped for, no big names from the sporting world were revealed during the trial's four months, often interrupted due to the coronavirus pandemic.

This is the first major prosecution under anti-doping legislation introduced in Germany in 2015.

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