Defunct Irish cycling team Aqua Blue Sport are likely to be stripped of their only Grand Tour stage win after one of their former riders reportedly admitted to blood doping.

Austrian newspaper Tiroler Tageszeitung have reported that Stefan Denifl, who won a stage of the 2017 Vuelta a Espana in Aqua Blue colours, has made a confession.

The Austrian rider was arrested last week as part of an investigation by German and Austrian police into doping in sport. Several other cyclists, skiers and a doctor were arrested.

Aqua Blue were the only Irish pro team in the peloton and they made their only appearance at a Grand Tour – cycling’s majors, the Tour de France, the Giro d’Italia and the Vuelta – in Spain two years ago.

The team went out of business suddenly last year, leaving their employees looking for new contracts before the start of the season.

Denifl was due to sign on with new outfit CCC Team in 2019, but it was announced recently that both sides had mutually agreed to terminate the contract due to the rider’s ‘personal reasons’.

The 31-year-old won three races in his professional career, by far the biggest of which was his victory on the mountainous stage 17 at the Vuelta two years ago.

There are many different types of blood doping, including blood transfusions, and they are all aimed at improving athletic performance by increasing aerobic capacity and endurance thanks to an increased red blood cell count.

It can be difficult to detect and over the years it has been common in cycling, a sport which is still dealing with a deep-seated doping culture.