The prosecutors' office declined to name the athlete arrested but said that his statements had set off an investigation in Germany that led to those arrests and others.
Munich's state prosecutor's office said last week the investigation was triggered by statements made earlier this year to a German broadcaster by Austrian cross-country skier and doping offender Johannes Duerr.
"In the course of the doping investigation a suspicion arose regarding another cross-country skier who had himself previously through his own statements set in motion the investigation in Germany against a sports doctor in Erfurt," the Innsbruck prosecutors' office said in a statement.
"These new investigation findings made it necessary to arrest the man at midday today," it added.
Two Austrians were among five athletes arrested last Wednesday at the world championships in the Austrian resort of Seefeld on suspicion of blood doping.
Two people, including a 40-year-old sports doctor whom police believe to have been at the centre of an international doping ring run out of the German city of Erfurt, were arrested in Germany the same day.
The prosecutors' office said it must decide within 48 hours whether to remand the athlete in custody or release him.
On Monday, Austrian cyclist Georg Preidler, who was part of the French elite team Groupama-FDJ, also admitted to doping. His team said he had "blood taken" in 2018.
(Reporting by Francois Murphy; Editing by Christian Radnedge)
