Former Spanish mountain bike rider Alberto Leon, one of six people accused last month as part of a probe into sports doping, was found dead in an apparent suicide, reports said on Monday.

Leon was found hanged at his home at San Lorenzo del Escorial near Madrid, radio Cadena Ser and other media outlets reported.

In December he was accused of public health offences and trafficking in illegal substances as part of a major police investigation into a doping network known as Operation Greyhound.

Leon allegedly provided doping products to athletes.

Among the others accused are world steeplechase champion Marta Dominguez and doctor Eufemiano Fuentes who was implicated in another major investigation into doping, the 2006 Operation Puerto which focused on cyclists.

Leon was also under investigation as part of that operation. Former Tour de France winner Jan Ullrich and Giro d'Italia winner Ivan Basso were among the riders caught up in Operation Puerto.

The other accused in Operation Greyhound are Dominguez's coach, Cesar Perez; athlete Alberto Garcia; fitness trainer Manuel Pascua Piqueras and agent Jose Alonso Valero.

Police began their investigation in April 2010 after becoming aware of a group that appeared to be aiding elite athletes who wanted to dope.

Operation Greyhound is the third recent police investigation into doping in Spanish sports after Operation Puerto and Operation Grial, carried out in 2009.