If found guilty by the Belgian National Cycling Federation (RLVB), Hoste faces a fine of up 300,000 Euros and a two-year suspension. The 35-year-old would also lose all his results from July 2008 to December 2010, which would include fourth and sixth-place finishes in Paris-Roubaix.
Hoste announced his retirement on December 1, 2012 citing back problems.
According to nieuwsblad.be, the case hinges on three samples – from 2008 following the Tour de France, and two in 2010.
Hoste is a three-time Belgian national time trial champion and a strong Classics contender. He finished second in the Tour of Flanders on three occasions, losing out to Steffen Wesemann in 2004, Tom Boonen in 2006 and Alessandro Ballan in 2007.